title: SQL server Login and User
body: <p>I am confused with Login and User. I found following in articles :
  A "Login" grants the principal entry into the SERVER.
  A "User" grants a login entry into a single DATABASE.
  One "Login" can be associated with many users (one per database).</p>
  
  <p>I can understand it theoretically. But, I think I might not have understood this practically.</p>
  
  <p>I created a Login in my SQL server 2008 management studio by right clicking SERVERNAME=>SECURITY=>LOGIN. The default database was "master". Now, I can log into sql server with this login name and password. I noticed that if I change the default database in Login properties to a specific database, I cannot login again with this credential. I reverted back to "master" and it works. What happened here?</p>
  
  <p>Also, why do we need users? I created a user by right clicking DATABASENAME=>SECURITY=>USERS. I cannot relogin with this user credential. So, what is the purpose we need this for. I can understand the theory of this answer but I need little more explanations to make sense.</p>
  
  <p>Also, I am a .net developer, so I would like to know, what are the credentials provided in sql connection strings. Are they login or user or can be any of these?</p>