Hi,
The abbrevation of basis is Business Application Software
Integrated solution.
Basis is a function/module (like Finance, Materials, Quality,
Production etc)in SAP. Basis is the Administoring programs which
administer the SAP Application. Basis Administrator administers the
SAP application using the tools or transactions available under
Basis component. Normal functions like creating user, assigning
access rights, backup, restore, check the performance are some of
the transaction available under Basis component in SAP. Earlier
upto SAP version 4.6 there is only basis version available and all
other functional component where add ons. From sap version 4.7
Basis is integrated with all other functional module. Hope this
helps