SPL Processing

Can someone explain in basic terms as possible the purpose of each of these programs used in SPL processing?  I understand that these are executed after an XML file is received from our 3rd party supplier of the Sanctioned Party List?

1. /SAPSLL/SPL_CUS_APP_BUFF_RESET
2. /SAPSLL/SPL_CREATE_SEARCHTERMS
3. /SAPSLL/SPL_INDEX_CREATE
4. /SAPSLL/SPL_CREATE_SEARCHTADRC
5. /SAPSLL/CHECK_SCEN_C1M_LO

For example, what I need to know is:

In  1) What is the "application buffer"?  Where can it be seen?

In  2) What are "searchterms"?  Can a list of search terms be seen?

In  3) What is the "index"?

In 4) What is the "search terms for address"?

In 5) What is the purpose of this step?