The purpose of sp_who and sp_who2 is the same and both are used to get information about current users, sessions, and processes in an instance of the Microsoft SQL Server Database Engine. However, there are some differences in both of these. Given below are some of the key differences.
sp_who supports the limited columns information about currently running processes in the SQL Server while sp_who2 supports some extra columns' information about currently running processes in the SQL Server.
The sp_who command is documented and officially supported by Microsoft while the sp_who2 command is undocumented and doesn’t have any support from Microsoft.
sp_who2 is more widely used for better information on the running process.
The following images show a clear picture of sp_who and sp_who2.
sp_who
sp_who2