Process management — ps, kill, lsof, htop

## See processes
`ps aux` — all processes
`ps aux | grep name` — filter by name
`pgrep name` — get PID by name
`htop` / `top` — interactive monitor

## Kill
`kill PID` — graceful (SIGTERM)
`kill -9 PID` — force (SIGKILL)
`pkill name` — kill by name
`killall name` — kill all matching

## Network
`lsof -i :PORT` — what's using a port
`netstat -tlnp` — listening TCP ports (Linux)
`ss -tlnp` — modern netstat replacement

## Background jobs (shell)
`cmd &` — run in background
`jobs` — list backgrounded
`fg %1` — bring job 1 to foreground