sys.sql_logins returns information about SQL Server authentication logins.
Example:
SELECT m.name, m.principal_id, m.type_desc, m.password_hash FROM master.sys.sql_logins m
Result:
name principal_id type_desc password_hash
sa 1 SQL_LOGIN 0x0200D225062FC1F5301DB7D08706A19C5CC900AB979B59D33B8ACB61F5
D5FCCF9BA0CE660B47435B9A5BD1F06D63C56A4DC6FB69EA429978866AEE29FA440F4E3D
4AE336D3D2