OOTB Timer Jobs definitions

Working on OOTB Timer Jobs definitions and purpose, I'm getting puzzled to find out below timer jobs description and there purpose, What these jobs do in Farm.

1. Document Changed Anti-virus Processing

2. Document Full Crawl Anti-virus Processing

3. Document Full Crawl Blob Compression Processing

4. Dump site information

5. Dump web information

6. High Write Volume Sites Document Changed Anti-virus Processing

Any idea for these timer jobs.