1. FACEBOOK
Facebook is an online social networking service. Where the
users can share photos, add comments and like on your
friends picture. Users must register before using the site,
after which they may create a personal profile, add other
users as friends, exchange messages, and receive automatic
notifications when they update their profile.

2. YouTube is a video-sharing website, on
which users can upload, view and share
videos.
YouTube

3. Twitter is an online social networking and
microblogging service that enables users
to send and read "tweets", which are text
messages limited to 140 characters. Share
photo with your friends.
TWITTER

4. Snapchat is a photo messaging application
developed by Stanford University students.
Using the app, users can take photos,
record videos, add text and drawings, and
send them to a controlled list of recipients.
SNAPCHAT