Browser security

Each browser tab has its own separate bucket for running code in (these buckets are called "execution environments" in technical terms) - this means that in most cases the code in each tab is run completely separately, and the code in one tab cannot directly affect the code in another tab - or on another website. This is a good security measure - if this were not the case, then pirates could start writing code to steal information from other websites, and other such bad things.

Note: There are ways to send code and data between different websites/tabs in a safe manner, but these are advanced techniques that we won't cover in this course.