Twitter, Facebook, Instagram, and LinkedIn all have distinct uses. They were each created not as direct competition for the other but to fill a specific niche in the social networking world. Twitter was originally started so that people can post 140 character messages. People can also attach photos or articles, but the main focus is the message. Instagram on the other hand, highlights the photo. It is a place for posting pictures and while it allows you to caption your pictures, the main focus is the picture. Facebook allows you to share almost anything. The highlight of your post can be a message, a picture, an article, a video, or a website link. It is more versatile than the two aforementioned sites. LinkedIn is to connect people in professional circles. The site highlights connections with people in your field and is great for job searches. While there is overlap between the four social networking sites, they each have a specific function.