Copying SQL Server database
Are you just looking for a complete copy of the data to completely replace what already lives on the destination instance?  In that case, a full backup of the source database and a restore into the destination instance would be the cleanest and easiest route.

If you are looking at select data copying (i.e. you don't want all data, or you don't want to replace the destination data) then you'll need to have a logic layer between the two data sources.  Some ideas behind this would be SSIS, PowerShell, or any other tool to do some brain work between both SQL Server databases.  The tool to use would depend on the specifics of your need as well as your comfort level with all the options.