Comic Sans was designed by typographer Vincent Connare in 1994 when he was working with a test version of Microsoft. Microsoft chose to include it in Microsoft 95, Microsoft Office and Internet Explorer. It is an informal somewhat child-like font.
Many people love to hate Comic Sans and it is especially criticized when used for formal documents, such as official announcements and press releases.
Personally I rather like Comic Neue though I am sure lots of people hate that one too! I have always found sans serif fonts easier to read. When I studied print journalism we were taught to use sans serif fonts in headlines and serif fonts in the body text as the serifs on the letters ‘guided’ the eye along the rows of text. In online writing though, sans serif fonts are way more common as they do not ‘twitter’ on low resolution screens in the same way as serifs.