Facebook is a social media platform where users can post photos, write posts, and chat with friends. Twitter allows users to follow celebrities and see what activities they are doing or have done. Skype enables users to make video calls and see/talk to others through their webcams. Tumblr is a blogging platform where users can follow others, like/reblog posts, and create their own blog with images and text. Safety is important on social media because bullies may send threatening or harassing messages.