I'm having trouble finding out what "latest" and "pending" mean.

The context is: I want to monitor accounts for incoming transactions (RPC/IPC API) and call a function whenever any one of a number of monitored accounts receives ether which is "confirmed", as in, "sufficiently many blocks ago that the chances of double-spending are negligible".

I'm looking into filters; the words "pending" and "latest" keep cropping up. What do they mean?

Also, if there's also a reference implementation of the above API usage, I'd love to see it. Thanks.

I want to monitor accounts for incoming transactions (RPC/IPC API) and call a function whenever any one of a number of monitored accounts receives ether which is "confirmed", as in, "sufficiently many blocks ago that the chances of double-spending are negligible".

Is there a reference implementation of this?

I'm looking into filters and the words "pending" and "latest" keep cropping up. What do they mean?