web script language tag definition

I am new to web development. It's easy to see a lot tag starting with:

开发者_JAVA百科

<%=
<%!
<%@

What are these tag called? Is it from any specific scripting language? Can I find the reference on w3schools? Please help, thanks.

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That looks like JavaServer Pages. W3Schools doesn't have anything on it, but with the name you should be able to Google it and find a lot.