how to set server property in a connection string

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connectionstring

ASP.NET4

MVC5

Hi, I am a Beginner.
I Just Uploaded My ASP.NET MVC Site to a Host. But is does not works.
My Exact Question is in "server" property of bellow connection string:

connectionString="server=' ';database=' ';User Id= ' ';password=' ';"

should i put servers address or should i put (Local)?
if i should put server address, should i use servers IP or use my site URL? host owner gave me a port number to database. should i include the port number too? like x.x.x.x:2010

but database is in same server that my websites code are, then why should we use server's address instead of using (local) like we do in our PC.

thank you very much