**Trailing slash**
```
rsync src/ dest/ # -> dest/contents
rsync src  dest/ # -> dest/src/contents
```

**Useful options**
- -r: recursive
- -l: keep symlinks
- -p: keep permissions
- -t: keep modification times
- -z: compress during transfer
- -h: human-readable sizes
- -P: show progress (%) and keep partial files if interrupted
- -e: custom command (e.g. ssh with port)

**Sane default copy (no owner/group kept)**
```
rsync -rlptzhPe 'ssh -p 12345' ./ 192.168.1.100:/path/to/mybackup/
```