https://medium.com/young-coder/three-beginner-mistakes-in-html-1287381abbd6

Matthew MacDonaldBlockedUnblockFollowFollowingApr 21Browsers have a funny way of dealing with mistakes. If they can, they ignore problems and plow ahead.

In the not-so-distant past, there was a war between the people who wrote web standards (like HTML) and the people who wrote the web browsers. The web standards folk wanted browsers to be pickier, so that it would force web pages to become more virtuous. The web browser people just wanted everything to work for everybody as much of the time as possible, so that nothing ever looked broken. (Historical side note: the web standards people endorsed a standard called XHTML, while the web browser people picked a different standard called HTML5.)