SFTP on the command line:

connect: sftp your_account@server_name.tld
enter password when prompted, it will display an sftp prompt afterward

list local files:
sftp>lls

local directory:
sftp>:lpwd

list remote server files:
sftp>ls

remote server directory:
sftp>pwd

change to a different local directory:
sftp>lcd directory_name

change to a different remote server directory:
sftp>cd directory_name

download file from remote directory to local directory:
sftp>get file_example.ext

upload file from local directory to remote server directory:
sftp>put file_example.ext

open help file:
sftp>help

quit sftp:
sftp>quit