This post lists all the varieties nicely: ASP.NET "special" tags.
I would normally post this as a comment but there are a number of other dupes. I recall someone referring to them as "bee stings" (not official terminology) and the keywords I used to search for them were asp.net bee stings.
That said, here are some other dupes:
- What is the difference between <% %> and <%=%>?
- <%$, <%@, <%=, <%#…what’s the deal?
- When should I use # and = in ASP.NET controls?
