When i want connect sql with c# what is the code for do it

Answer 1

https://code.sololearn.com/cVWZaxPNp8Iq/?ref=app
https://code.sololearn.com/cwjaPa1z5i0o/?ref=app
https://code.sololearn.com/cX2C8M8otDZ3/?ref=app

Answer 2

https://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection(v=vs.110).aspx

Answer 3

what is mean server when i want connection