I am going to say follow def90 advice.

Yep analog device...depending on your budget you might want to upgrade the hardware to get better quality video. However, if it is doing the job the way you want it - - no real requirement to do anything.

With the age of the hardware it will be harder to upgrade with new old stock on video cameras. Network cable; so getting it to the outside word is 'possible'. USB ports would indicate either mice /keyboard support - or possible external hard drive access. Looks like dip switches next to what I think might be power input. You might be able to find a user's manual to help with some of the technical questions.