scp remote_username@remote_addr:/remote/path/file.txt .
# download: remote -> local
scp user@remote_host:remote_file local_file
# upload: local -> remote
scp local_file user@remote_host:remote_file
# upload: with key
scp -i key.pem local_file user@remote_host:remote_file
# upload: specify port
scp -P 2222 local_file user@remote_host:remote_file
scp osxdaily@192.168.0.4:filename.zip ~/Desktop/