Facebook is an American for-profit corporation and an online social media and social networking service based in Menlo Park, California. The Facebook website was launched on February 4, 2004, by Mark Zuckerberg, along with fellow Harvard College students and roommates, Eduardo Saverin, Andrew McCollum, Dustin Moskovitz, and Chris Hughes.

Instagram is a mobile photo-sharing application and service that allows users to share pictures and videos either publicly or privately on the service, as well as through a variety of other social networking platforms, such as Facebook, Twitter, Tumblr, and Flickr. It was created by Kevin Systrom and Mike Krieger, and launched in October 2010 as a free mobile app exclusively for the iOS mobile operating system. A version for Android devices was released two years later, in April 2012, followed by apps for Windows 10 Mobile in April 2016, and Windows 10 in October 2016.

LinkedIn is a business and employment-oriented social networking service that operates via websites and mobile apps. Founded on December 28, 2002, and launched on May 5, 2003, it is mainly used for professional networking, including employers posting jobs and job seekers posting their CVs. As of 2015, most of the company's revenue came from selling access to information about its members to recruiters and sales professionals. As of September 2016, LinkedIn had more than 467 million accounts, out of which more than 106 million are active. LinkedIn allows members (both workers and employers) to create profiles and "connections" to each other in an online social network which may represent real-world professional relationships. Members can invite anyone (whether an existing member or not) to become a connection.

VK (VKontakte) is the largest European online social media and social networking service. It is available in several languages and is especially popular among Russian-speaking users. VK allows users to message each other publicly or privately, to create groups, public pages and events, share and tag images, audio and video, and to play browser-based games. It is based in Saint Petersburg, Russia.

Viber is a free, cross-platform instant messaging and voice over IP (VoIP) application that was first developed and popularized by the Israeli company Viber Media that was bought by the Japanese multinational company Rakuten. In addition to instant messaging, users can exchange images, video and audio media messages by sending files to each other. As of December 2016, Viber had 800 million registered users.

Tencent QQ, popularly known as QQ, is an instant messaging software service developed by a Chinese company named Tencent Holdings Limited. QQ also offers a variety of services, including online social games, music, shopping, microblogging, movies, and group and voice chat. The logo and mascot is a small penguin wearing a red scarf.

At the end of June 2016, there were 899 million active QQ accounts. A peak number of over 200 million simultaneous online QQ users was recorded as of April 2014.

Zalo is a free messaging and calling application that runs on the mobile platform.

WeChat is a social media (instant messaging, commerce and payment services) application developed by Tencent. It was first released in 2011 and by 2016 it was one of the largest standalone messaging apps by monthly active users, with over 889 million active users. However, as of 2017, WeChat has not been successful in penetrating international markets outside of China. WeChat je sociální média - aplikace vyvinutá společností Tencent. Poprvé byla vydána v roce 2011 a do roku 2016 to byl jeden z největších aplikací samostatný messaging podle měsíčních aktivních uživatelů, s více než 889 milionů aktivních uživatelů. Nicméně, jak v roce 2017, WeChat nebylo úspěšné pronikání na mezinárodní trhy mimo Čínu.

Odnoklassniki, OK.ru is a social network service for classmates and old friends. It is popular in the Russian Federation and former Soviet Republics. The site was developed by Albert Popkov on March 4, 2006.

The website currently has more than 200 million registered users and 45 million daily unique visitors. Users have to be at least seven years old to make an account. Odnoklassniki also currently has an Alexa Internet traffic ranking of 56 worldwide and 7 for Russia. Revenues in the first quarter of 2008 for Odnoklassniki amounted to $3.3 million.