Taking JAVA I this semester and apparently the professor took out applets from the curriculum for the first time.

Learn Java FX instead if you have extra time

Good. Applets are cancer

can someone explain the significance?

@3stacks Applets are not commonly used anymore. Applets are like Java programs that run in the web browser. Kind of like how a Flash animation would run in the browser, self-contained.

you may safely Skip all GUI related topics, including swt swing applet Javafx awt jsp jface.....
most of the cases Java do not used for GUI, when you need to do all the stuff learned at school are useless, u may end up using drag and drop tools or need to do serious hacking
here r some cases using Java GUI tech:
eclipse plugins awt
intelij plugins swing
maintenance of struts jsp