What is a Data Source and where can I find it in SSMS? I have just recently started using SQL Server Management Studio. After some hitches, I have managed to create a Database. Inside the DB I have also created some Tables and populate them. 

Now I am trying another software that needs to be connected to this DB. When running the software it asks me:

"Data Souce" and "Catalog"

Apparently the "Catalog" is the name of the DB I have created but I don't know what "Data Source" refers. 
It must be a rather begineer question but what does "Data Source" refers to?
Yes, Initial Catalog refers to the database name and Data Source refers to your server name. 

See more on SQL Server connection strings