Non-SysAdmins have been denied permission to run DTS Execution job steps without a proxy account. The step failed.

I am trying to follow the steps to create a proxy account.  I am looking at http://www.mssqltips.com/sqlservertip/2163/running-a-ssis-package-from-sql-server-agent-using-a-proxy-account/.

--Script #1 - Creating a credential to be used by proxy
USE MASTER
GO
--Drop the credential if it is already existing
IF EXISTS (SELECT 1 FROM sys.credentials WHERE name = N'SSISProxyCredentials')
BEGIN
DROP CREDENTIAL [SSISProxyCredentials]
END
GO
CREATE CREDENTIAL [SSISProxyCredentials]
WITH IDENTITY = N'ARSHADALI-LAP\SSISProxyDemoUser',
SECRET = N'abcd@0987'
GO

I am not sure what logon this is:  ARSHADALI-LAP\SSISProxyDemoUser.  Is this a Service Account created through Active Directory?  And is this logon then given sysadmin privileges on the SQL Server?

Or is this the logon of the Active Directory Group that the user belongs to who wants to create SSIS packages and run them?

lcerni