How can another computer on my network monitor my computers web searching history?

C M: How can another computer on my network monitor my computers web searching history?
Just as the title says, how can another computer on my network monitor web history that has been physically typed and search. For example things I may have typed into google. How is it that this is showing up on the web history of another computer in my house hold? Ive made sure all networking connections are closed, all files folder and everything are non-sharable. I consider my self pretty tech savy as well so I am at a loss here.

Answers and Views:

Answer by Jane.Hu
Even they can monitor your online activities realtime asa long as they deploy a monitor tool like a network sniffer. You can also do that, and it also help when there’s network prolems happened. It helps to quickly locate the network bottleneck and give you expert suggestions on how to slove the problems. So it also called network security guarian.

Answer by Ding
keylogger can monitor ur seraching activity.

Answer by Beyond
Share files can result in such problems, but it’s not the only reason.
Nowadays, monitoring software such as LaneCat, are here and there.
Even though, you are as careful as you can, someone just manage to know what they want to know