Leosghost - 12:38 am on May 17, 2012 (gmt 0)
What it is? can depend on many things ..primarily the config' / specs of the machine you are using ..also the OS, how many tabs you have open etc etc..
Flash is processor intensive ( each instance in each tab makes it more hungry )..Firefox leaks memory ..
Websites and webpages are more complex and use more machine resources to render than they used to..open enough tabs, with enough things "going on" in each page..and enough background processes and windows open..and depending on the OS and the machine spec and the browser..it will all go TU and freeze..
Change something ..how you browse, what you browse with, where you browse..or add more RAM and/ or a faster CPU and graphics card..