user872: I am currently playing the Italian opening with the white pieces.
[FEN ""]
1.e4 e5 2.Nf3 Nc6 3.Bc4

I have been training with a higher rating player, who suggests to switch to the Spanish opening(Ruy Lopez).
[FEN ""]
1.e4 e5 2.Nf3 Nc6 3.Bb5

I would like to ask, is the Spanish so much better than the Italian that it makes it worth changing? Furthermore, in the Spanish opening, does black have sharp variations that could be used against white?

user19861: The Spanish (Ruy Lopez) is OBJECTIVELY better which means if you play most of your games against GMs and 3000+ rated engines it should be your main choice as a 1.e4 player.
However, for most most normal people the Italian is going to give better results.
I wouldn't recommend the main lines Ruys for anyone unless they have aspirations of reaching IM level or higher. And realistically if you're over 12 and asking this question thinking you can become an IM your aspirations are probably unrealistic. There is a ton of theory in the Ruy and the positional play can be extremely subtle. Most people would be better off spending their time studying tactics.

user2042: Let us start with the Italian game.
Although it was long long ago since I was playing this opening, there are good reasons why it is not played anymore. The main reason it is not popular any more is the failure of the Moeller attack:
[fen ""]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4. c3 Nf6 5.d4 exd4 6.cxd4 Bb4 7.Nc3 Nxe4 8.O-O Bxc3 9.d5 Bf6 10.Re1 Ne7 11.Rxe4 d6 12.Bg5 Bxg5 13.Nxg5 h6 ( 13...O-O 14.Nxh7!= ) 14.Qe2 hxg5 15.Re1 Be6 16.dxe6 f6 17.Re3 c6

In the old days people played the Moeller attack and in the beginning things were good for White --- sacrifice a pawn and get strong initiative --- but Black found a way to defend the attack --- see the lines above --- and the main line was destroyed. White tried with quiet d3 and to prepare d4 as in the Spanish game ( Ruy Lopez ) but had no success.
People tried with the Scotch Gambit --- mainly the Max Lange Attack --- but Black did not need much time to find antidote-that line failed White too so it was abandoned.
Tthe same happened with the Traxler attack and it was abandoned too.
The Evans Gambit had the same faith-I think Lasker was the one who proved that Black can at certain point return the pawn and obtain better chances due to better pawn structure.
Nowadays, people seek various ways to improve these old lines but nothing tangible was found-either Black can sidestep the improvements or they give equal play.
Now the good stuff --- the Ruy Lopez! After the moves:
[fen ""]

1.e4 e5 2.Nf3 Nc6 3.Bb5

we reach the tabia. We notice that there is no symmetry as in the Italian Game. Moreover, an important thing with  the Ruy Lopez is that White exerts maximum possible pressure on the center. That is the reason why it is better than Italian game, where center control is divided equally.
Because Black is under pressure he needs to make concessions, usually via a6 and then b5 to chase away the bishop-which leaves him with weak c pawn. Because of advantage in the center and healthier pawn structure White has a long initiative and Black needs to play carefully to free himself. This usually manifests in White having a king side attack, or slight but long lasting positional pressure.
Furthermore, in the Spanish game, White can create center formation he likes thanks to his flexible d4+e4 pawn phalanx, something he can not do in the Italian game. This means that White can play with fixed center ( pawn e4 vs e5 ) , semi open center ( pawn e4 vs d6 ) or closed one ( e4+d5 pawns vs d6+e5 ) and that gives him opportunity to try various transpositional tricks to outsmart Black-something that Italian game can not give you since the center is fixed and symmetric.
To summarize:
The Ruy Lopez gives you a slight advantage in the center, slight initiative, great flexibility in steering the game, healthier pawn structure and great transpositional resources to outsmart your opponent.
If you wish to improve as a player you should play this opening for a while, so you can learn how to play with different center formations. It is good for practising how to "cash in" the king side attack.

Futhermore, in the Spanish does black have sharper continuations that he can throw against white?

Yes he does --- the variation you seek is the Marshall attack. It is very dangerous, and, as it is based on positional grounds, i doubt that a refutation of this gambit can be found. I think the current theoretical standing is unclear. Be warned, you must know theory very well to play against this line.
If you have further questions leave a comment and I will respond.
Sorry for incoherent answer, I wrote thoughts as they came to me. I could write a small book on this topic-there is so much to say about this-so if you need further information feel free to ask.
EDITED ON OPs REQUEST:

I am trying to understand if it is a lot better or only slightly better.

It is way better than Italian game.
Black defends statically in Ruy Lopez, there are no counter-attacks ( except the Marshall attack of course ) so he needs to suffer a little in order to get counter-play.
Since you have an ideal center ---d4+e4 pawn formation --- you have a slight space advantage. You also decide what type of game shall be played --- open or closed --- depending on your decision to close or open the center.
You get a king-side attack, and Black needs to defend himself --- his counter-play on the queen-side is not sufficient. Be warned --- the Ruy Lopez is highly complicated to play for both sides but that is the reason people play it with both colors --- because both sides must play accurately.
The reason I would not recommend it for Black is that Black lacks active counter-play, so he needs to defend for a long time, before he generates chances, and that is just too much for me.
Generally speaking, White has easier play in the Ruy Lopez. He "calls all the shots" most of the time, and Black needs to repel White's threats first, and only then try to generate counter-play.
This is one of the main reasons why Black often answers to 1.e4 with the Sicilian or the French defense.
This was my opinion, supported by my current knowledge and experience in the Ruy Lopez and Italian game.
I must say that I have stopped playing 1.e4 long ago and that many things might have changed today but to test my claims it would be best to obtain good repertoire books on Ruy Lopez ( although I strongly believe that conclusions from those book will mainly support my conclusions ).
Hopefully this answer sheds some light.
Best regards.

872: <p>I am currently playing the Italian opening with the white pieces.</p>
<pre><code>[FEN &quot;&quot;]
1.e4 e5 2.Nf3 Nc6 3.Bc4
</code></pre>
<p>I have been training with a higher rating player, who suggests to switch to the Spanish opening(Ruy Lopez).</p>
<pre><code>[FEN &quot;&quot;]
1.e4 e5 2.Nf3 Nc6 3.Bb5
</code></pre>
<p>I would like to ask, is the Spanish <strong>so much better</strong> than the Italian that it makes it worth changing? Furthermore, in the Spanish opening, does black have sharp variations that could be used against white?</p>
 19861: <p>The Spanish (Ruy Lopez) is OBJECTIVELY better which means if you play most of your games against GMs and 3000+ rated engines it should be your main choice as a 1.e4 player.</p>
<p>However, for most most normal people the Italian is going to give better results.</p>
<p>I wouldn't recommend the main lines Ruys for anyone unless they have aspirations of reaching IM level or higher. And realistically if you're over 12 and asking this question thinking you can become an IM your aspirations are probably unrealistic. There is a ton of theory in the Ruy and the positional play can be extremely subtle. Most people would be better off spending their time studying tactics.</p>
 2042: <p>Let us start with the <a href="https://en.wikipedia.org/wiki/Giuoco_Piano" rel="nofollow noreferrer"><em>Italian game</em></a>.</p>
<p>Although it was long long ago since I was playing this opening, there are good reasons why it is not played anymore. The main reason it is not popular any more is the failure of the <a href="https://en.wikipedia.org/wiki/Giuoco_Piano#7.Nc3_(including_Greco_Variation_and_M%C3%B8ller_Attack)" rel="nofollow noreferrer"><em>Moeller attack</em></a>:</p>
<pre><code>[fen &quot;&quot;]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4. c3 Nf6 5.d4 exd4 6.cxd4 Bb4 7.Nc3 Nxe4 8.O-O Bxc3 9.d5 Bf6 10.Re1 Ne7 11.Rxe4 d6 12.Bg5 Bxg5 13.Nxg5 h6 ( 13...O-O 14.Nxh7!= ) 14.Qe2 hxg5 15.Re1 Be6 16.dxe6 f6 17.Re3 c6
</code></pre>
<p>In the old days people played the <em>Moeller attack</em> and in the beginning things were good for White --- sacrifice a pawn and get strong initiative --- but Black found a way to defend the attack --- see the lines above --- and the main line was destroyed. White tried with quiet <code>d3</code> and to prepare <code>d4</code> as in the <em>Spanish game ( <a href="https://en.wikipedia.org/wiki/Ruy_Lopez" rel="nofollow noreferrer">Ruy Lopez</a> )</em> but had no success.</p>
<p>People tried with the <a href="https://en.wikipedia.org/wiki/Scotch_Game#Scotch_Gambit" rel="nofollow noreferrer"><em>Scotch Gambit</em></a> --- mainly the <a href="https://en.wikipedia.org/wiki/Two_Knights_Defense,_Max_Lange_Attack" rel="nofollow noreferrer"><em>Max Lange Attack</em></a> --- but Black did not need much time to find antidote-that line failed White too so it was abandoned.</p>
<p>Tthe same happened with the <a href="https://en.wikipedia.org/wiki/Two_Knights_Defense#Traxler_Counterattack:_4...Bc5" rel="nofollow noreferrer"><em>Traxler attack</em></a> and it was abandoned too.</p>
<p>The <a href="https://en.wikipedia.org/wiki/Evans_Gambit" rel="nofollow noreferrer"><em>Evans Gambit</em></a> had the same faith-I think <em>Lasker</em> was the one who proved that Black can at certain point return the pawn and obtain better chances due to better pawn structure.</p>
<p>Nowadays, people seek various ways to improve these old lines but nothing tangible was found-either Black can <strong>sidestep</strong> the improvements or they give equal play.</p>
<p>Now the good stuff --- the <em>Ruy Lopez</em>! After the moves:</p>
<pre><code>[fen &quot;&quot;]

1.e4 e5 2.Nf3 Nc6 3.Bb5
</code></pre>
<p>we reach the <a href="https://en.wikipedia.org/wiki/Glossary_of_chess#tabia" rel="nofollow noreferrer"><em>tabia</em></a>. We notice that there is <strong>no symmetry</strong> as in the <em>Italian Game</em>. Moreover, an important thing with  the <em>Ruy Lopez</em> is that White exerts <strong>maximum</strong> possible pressure on the center. That is the reason why it is better than <em>Italian game</em>, where center control is divided <strong>equally</strong>.</p>
<p>Because Black is under pressure he <strong>needs to make concessions</strong>, usually via <code>a6</code> and then <code>b5</code> to chase away the bishop-which leaves him with weak <code>c</code> pawn. <strong>Because of advantage in the center and healthier pawn structure White has a long initiative and Black needs to play carefully to free himself.</strong> This usually manifests in White having a king side attack, or slight but long lasting positional pressure.</p>
<p>Furthermore, in the <em>Spanish game</em>, White <strong>can create center formation he likes</strong> thanks to his <strong>flexible</strong> <code>d4+e4</code> pawn phalanx, something he <strong>can not do</strong> in the <em>Italian game</em>. This means that White can play with <strong>fixed center ( pawn <code>e4</code> vs <code>e5</code> ) , semi open center ( pawn <code>e4</code> vs <code>d6</code> ) or closed one ( <code>e4+d5</code> pawns vs <code>d6+e5</code> )</strong> and that gives him opportunity to try various <strong>transpositional tricks</strong> to outsmart Black-something that <em>Italian game</em> can not give you since the center is <strong>fixed and symmetric.</strong></p>
<p>To summarize:</p>
<p>The <em>Ruy Lopez</em> gives you a slight advantage in the center, slight initiative, great flexibility in steering the game, healthier pawn structure and great transpositional resources to outsmart your opponent.</p>
<p>If you wish to improve as a player you should play this opening for a while, so you can learn how to play with different center formations. It is good for practising how to &quot;cash in&quot; the king side attack.</p>
<blockquote>
<p>Futhermore, in the Spanish does black have sharper continuations that he can throw against white?</p>
</blockquote>
<p>Yes he does --- the variation you seek is the <a href="https://en.wikipedia.org/wiki/Ruy_Lopez#Marshall_Attack" rel="nofollow noreferrer"><em>Marshall attack</em></a>. It is very dangerous, and, as it is based on positional grounds, i doubt that a refutation of this gambit can be found. I think the current theoretical standing is <em>unclear</em>. Be warned, you must know theory very well to play against this line.</p>
<p>If you have further questions leave a comment and I will respond.</p>
<p>Sorry for incoherent answer, I wrote thoughts as they came to me. I could write a small book on this topic-there is so much to say about this-so if you need further information feel free to ask.</p>
<p><strong>EDITED ON OPs REQUEST:</strong></p>
<blockquote>
<p>I am trying to understand if it is a lot better or only slightly better.</p>
</blockquote>
<p>It is <strong>way better</strong> than <em>Italian game.</em></p>
<p>Black defends <strong>statically</strong> in <em>Ruy Lopez</em>, there are <strong>no counter-attacks</strong> ( except the <em>Marshall attack</em> of course ) so he needs to suffer a little in order to get counter-play.</p>
<p>Since you have an <strong>ideal center</strong> ---<code>d4+e4</code> pawn formation --- you have a slight space advantage. You also decide what type of game shall be played --- open or closed --- depending on your decision to close or open the center.</p>
<p>You get a king-side attack, and Black <strong>needs to defend himself</strong> --- his counter-play on the queen-side is not sufficient. Be warned --- the <em>Ruy Lopez</em> is <strong>highly complicated</strong> to play for both sides but that is the reason people play it with both colors --- because <strong>both sides must play accurately.</strong></p>
<p>The reason I would not recommend it for Black is that Black lacks active counter-play, so he needs to defend for a long time, before he generates chances, and that is just too much for me.</p>
<p>Generally speaking, White has easier play in the <em>Ruy Lopez</em>. He &quot;calls all the shots&quot; most of the time, and Black needs to <strong>repel White's threats first</strong>, and only then try to generate counter-play.</p>
<p>This is one of the main reasons why Black often answers to <code>1.e4</code> with the <a href="https://en.wikipedia.org/wiki/Sicilian_Defence" rel="nofollow noreferrer"><em>Sicilian</em></a> or the <a href="https://en.wikipedia.org/wiki/French_Defence" rel="nofollow noreferrer"><em>French defense</em></a>.</p>
<p>This was my opinion, supported by my current knowledge and experience in the <em>Ruy Lopez</em> and <em>Italian game</em>.</p>
<p>I must say that I have stopped playing <code>1.e4</code> long ago and that many things might have changed today but to test my claims it would be best to obtain good repertoire books on <em>Ruy Lopez</em> ( although I <strong>strongly</strong> believe that conclusions from those book will <strong>mainly support</strong> my conclusions ).</p>
<p>Hopefully this answer sheds some light.</p>
<p>Best regards.</p>
