SafeBrowsing Client?

[GaryT]

Hi folks
Pray tell, what is a safebrowsing client and what would be a typical
association with the big "G".

My browser (Firefox) has several safebrowsing URLs in the config file
and I fail to see the relationship between that and web searches.

Does it identify me as a safe user and it's okay to search for me?
OR
Could it mean that I've been "had" somewhere along the way?
Or, is it simply a means of keeping track of my activities?

Does anyone really understand these things?

Thanks
GaryT