A web browser is a computer program which downloads and displays web pages on the World Wide Web (or a local device). The original internet browser was NCSA Mosaic. Before long, however, Netscape and AOL became most popular, while NCSA Mosaic became obsolete.
There are four major web browsers currently in use; Edge (formerly Internet Explorer), Firefox, Safari, and the Chromium-based Google Chrome. Google Chrome currently holds the largest "market share" in desktop browsing. There are many other web browsers as well, including Brave, Vivaldi, and Opera.
Other browsers are also carving niches such as Dolphin for Android phones, and Pale Moon for Atom processors.