user33521: I’m new to chess and I had my queen on the left one space away from the king which was on the right and he was unprotected, is that check?
E.g., take the following sample position (note: not provided by the OP - if the OP would like to post the position they had in mind, please feel free to delete this edit):
8/8/8/8/2Qk4/8/8/2R3K1 w - - 0 1


user15793: 
queen on the left one space away from the king

This is rather unclear, because we don't know what do you mean by the king being "one space away": is it on the same rank (row) or on different ranks?
In any case:

This is check:

[Title "This is check"]
[FEN "8/8/8/2q1K/8/8/8/8 w - - 0 1"]

 

This is not check:

[Title "This is not check"]
[FEN "8/8/4K/2q/8/8/8/8 w - - 0 1"]


user26006: Ultra-simple version:
"Check" means "If you don't do something to stop it, one of my pieces can take your King on my next turn".

user18809: After making your move, imagine it's your turn again. Would your queen be able to capture the enemy king? If yes, your opponent is in check. It also doesn't matter if some other piece protects that square or not.
If there's no legal move your opponent can do do remove their king from the danger, then you're not just giving check, but also checkmate!

33521: <p>I’m new to chess and I had my queen on the left one space away from the king which was on the right and he was unprotected, is that check?</p>
<p>E.g., take the following sample position (note: not provided by the OP - if the OP would like to post the position they had in mind, please feel free to delete this edit):</p>
<pre><code>8/8/8/8/2Qk4/8/8/2R3K1 w - - 0 1
</code></pre>
 15793: <blockquote>
<p>queen on the left one space away from the king</p>
</blockquote>
<p>This is rather unclear, because we don't know what do you mean by the king being &quot;one space away&quot;: is it on the same rank (row) or on different ranks?<br />
In any case:</p>
<ul>
<li>This is check:</li>
</ul>
<pre><code>[Title &quot;This is check&quot;]
[FEN &quot;8/8/8/2q1K/8/8/8/8 w - - 0 1&quot;]
</code></pre>
<p> </p>
<ul>
<li>This is not check:</li>
</ul>
<pre><code>[Title &quot;This is not check&quot;]
[FEN &quot;8/8/4K/2q/8/8/8/8 w - - 0 1&quot;]
</code></pre>
 26006: <p>Ultra-simple version:</p>
<p>&quot;Check&quot; means &quot;If you don't do something to stop it, one of my pieces can take your King on my next turn&quot;.</p>
 18809: <p>After making your move, imagine it's your turn again. Would your queen be able to capture the enemy king? If yes, your opponent is in check. It also doesn't matter if some other piece protects that square or not.</p>
<p>If there's no legal move your opponent can do do remove their king from the danger, then you're not just giving check, but also checkmate!</p>
