FTP (File Transfer Protocol) is probably the most popular method of uploading files to a server; a wide array of FTP servers, such as vsftpd, and clients exist for every platform.
Pre-Flight Check
These instructions are intended specifically for installing the vsfptd on Ubuntu 14.04 LTS.
I’ll be working from a Liquid Web Core Managed Ubuntu 14.04 LTS server, and I’ll be logged in as root.

• Step 1: Install vsftpd
  Warning: FTP data is insecure; traffic is not encrypted, and all transmissions are clear text (including usernames, passwords, commands, and data). Consider securing your FTP connection with SSL/TLS.
  First, you’ll follow a simple best practice: ensuring the list of available packages is up to date before installing anything new.

apt-get update

Then let’s install vsftpd and any required packages:

apt-get -y install vsftpd

• Step 2: Configure vsftpd
  For a refresher on editing files with vim see: New User Tutorial: Overview of the Vim Text Editor
  Let’s edit the configuration file for vsftpd:

vim /etc/vsftpd.conf

Disallow anonymous, unidentified users to access files via FTP; change the anonymous_enable setting to NO:

anonymous_enable=NO

Allow local uses to login by changing the local_enable setting to YES:

local_enable=YES

If you want local user to be able to write to a directory, then change the write_enable setting to YES:

write_enable=YES

Local users will be ‘chroot jailed’ and they will be denied access to any other part of the server; change the chroot_local_usersetting to YES:

chroot_local_user=YES

Exit and save the file with the command :wq.
Restart the vsftpd service:

service vsftpd restart

• Step 3: Configure the User’s Home Directory
  With certain version of vsftpd you may receive the following error: 500 OOPS: vsftpd: refusing to run with writable root inside chroot().
  Not to worry! Create a new directory for the user receiving the error (user2 in this case) that is a subdirectory of their home directory (/home/user2). For example:
  Fix permissions for user2‘s home directory:

chmod a-w /home/user2/

Make a new directory for uploading files:

mkdir /home/user2/files
chown user2:user2 /home/user2/files/