I’m guessing that most people who use Google Drive and associated Apps will be doing so via Google’s Chrome browser.
Chrome is written to be a robust, fast and efficient browser. I’m not going to venture too deeply into the geeky underworld of how it actually works (you can always check out the source code of it’s open-source sister, Chromium, if you like), but one of the techniques it uses to prevent one hinky page from crashing the whole browser is to separate different tasks into separate processes. This is like having a number of separate programs all running at once, each looking after its own resources (such as memory allocation, calls to the BIOS, and so on). There’s a process for each tab you have open, and one for each extension you have activated.
That’s why, if things slow to a crawl, you may want to isolate and kill the faulty process. You can see all the currently-running processes in your operating system’s Task Manager (I run Linux, but I believe Windows has something similar):
The ones labelled chrome in the image above are the ones you want.
Unfortunately, there’s no other meaningful description offered – which task is which? You may be able to work out from the list which process is the one playing up, but it would be handy to know what it’s actually supposed to be doing before you close it!
Luckily, Chrome helps again, by having its own task manager. From the Chrome settings button, select More tools and then Task manager (or use the key combination Shift + Esc):
Now you can see what each task is doing. If you need more information from the operating system’s Task Manager, you can match up the tasks using the Process ID (PID) value.