How to Start ftp service in Linux

1) FTP ( File Transfer Protocol ) is the simplest and most secure way to exchange files over    internet/intranet.
2) Transferring files from a client computer to a server  is called " Uploading" and transferring from a
 server to a client is “Downloading”
3) Port :21 is used for Control connection and Port 20 is used for Data Connection

Setting up and "ftp" server

SERVER SIDE :
Required package: vsftpd
Use this command to install the package (in Ubuntu): sudo apt-get install vsftpd

Changing configuration file "vsftpd.conf"; for allowing other users to access/write data.
vim /etc/vsftpd.conf
local_enable=YES
write_enable=YES
#anon_upload_enable=YES
After finishing the required changes 'save' and 'exit' from the .conf file

Now restart the "ftp" service using the following command:
sudo /etc/init.d/vsftpd restart
OR
service vsftpd start
Some other self explanatory commands:
service vsftpd status
service vsftpd stop
service vsftpd restart

CLIENT SIDE :
To do ftp to X.X.X.X IP PC we use,
ftp X.X.X.X
ftp>
Use the following commands within the 'ftp' command prompt:
Basic get/put commands
get filename
put filename
put/get commands with confirmation
mget filename
mput filename

bye-to exit from the ftp command prompt.