Twitter

What:  Twitter is a social media on which you can post pictures, short videos or short messages called tweets. You can follow people and be followed by anyone.

When: It was created in spring 2006 by the company Odea. It's creator Jack Dorsey, was inspired to create a website similar to flickr for the employees to use. 

Who:  It is available for the public since summer 2006.

Where: www.twitter.com

Pros and Cons

Pros:

• You can upload picture and videos with your messages.
• You can text messages to public screen.
• Easy to use with desktops or mobile devices.
• Twitter verifies the identity of businesses and celebrities so you can easily know if you are following the celebrity or a fan page.
• It has a "do not track" option.
• You can follow people

Cons:

• You can only post 140 characters per message which means you have to keep your messages really short and that it is more complicated to get informed of events on twitter.
• Like any other social media you have to be careful of what you post online.
• The server often crashes. Especially during events such as the olympics. 
• You can't decide on who follows you.
• You can't send private messages. You can send Direct messages, but they aren't considered private or public.
• Deleted tweets can still be found via the search toolbar. They are eventually deleted, but it may take time.
• The videos you post online can't be more than 6 seconds long or you can post your video on an other website that allows you to share it on twitter.