Difference Between SAP Notes and Support Package

Can Anybody tell me What is the Difference between SAP Notes and Support Package?
Which of them Should apply?

What is Add on Components? What is difference between PI and PI_BASIS?

I shall try to answer your questions to the best of my knowledge, there might be other vrsions or views for the same....any comments or feedback is welcome.

1. Difference between SAP Notes and Support Package?
Ans. When an end user of SAP finds a bug in the SAP product he reports the same to SAP support, SAP developers check the same and develop a correction for the same. This correction is sent to the customer in the form of a NOTE.

If the same or similar bug is reported by multiple clients or end users, then SAP recognizes such bug corrects them and collects all these corrections in one place and adds some enhancements to the earlier version of SAP and then calls this as a SUUPORT PACK. In simple words collection of

SAP NOTES is a SUPPORT PACK.

2. Which of them Should apply?
Ans. Depends on your or customers requirement.

3. What is Add on Components?
Ans. AddOn components are nothing but extra functionalities that do not come with main SAP product. Different organizations have different requirements, so SAP has recognized some main functionalities that are in demand and builds that functionality as a components, which can be integrated with the core SAP. so add on components sit above the core and access the same
dictionary objects or repository objects and perform the required funcionality.

4. What is difference between PI and PI_BASIS?
Ans. PI and PI_BASIS are two different components.

PI is the abbrevated form of Plug In. AddOn components or extension sets are installed above core SAP and they integrate or communicate with the core using PlugIn component.

PI_BASIS is the core component or a single version for different PlugIns.
Hope you can understand what I meant in the answers above.

Madhu :-)

A SAP Note fixes _one_ problem, Support packages are many SAP notes together (comparable with a single fix on windowsupdate and a service pack). One should consider running the latest packages since the most errors are fixed in there. Beware of dependencies between (which are also documented in separate SAP notes)

What is Add on Components? What is difference between PI and PI_BASIS?

An AddOn is specific coding that is delivered separately and can be (in most cases) updated without changing the base.

PI is the plugin to "plug" BI/BW and CRM to the system, it contains the extractors for BI and the qRFC part to sync CRM and R/3 (including the filters).

PI_BASIS is the plugin containing BASIS functionality (ALE p. ex.) It is planned to be able to also modularize this so that you can update PI_BASIS without doing a full upgrade but only upgrade this separate package through transaction SAINT.