btop for sure. Shows current processes and their resources usage, us can terminate and kill them from the program kinda like windoes task manager, shows CPU usage/temp, and ram, storage, and network use. Only big thing it doesnt have that I use is GPU monitoring, I use nvtop for that.
For stress testing, mprime is def best for CPU stress test. You may know it as prime95 on windows.
I have mixed feelings on this one, tbh
On one hand, that was actually the original name. That changed after WW2 and to be honest I kinda think the name was part of a greater campaign to make it seem as though, somehow, the military actions that followed in the next few decades in the middle east, Asia, Latin America, etc. were actually all just "defending" the US. Which is bullshit.
On the other hand, having perhaps the most insane president this country has ever seen saying that calling it war instead of defense because its more accurate to the current times is quite concerning to say the least.