What is applet? What are demerits of the applet?

1St Part:

An applet is a GUI program written in Java. Applets are embedded in a web page for e.g. a HTML page.eWhn the html page is viewed in a browser, the applet bytecodes are downloaded in the client machine and is executed by the JVM of the web browser.

2nd Part:

If A Java applet has the following disadvantages:
•   It requires a browser to have an integrated Java Virtual machine. Many browsers
face this incompatibility issue.

•   It can't start up until the JVM is running, and this may have significant startup
time the first time it is used.

• When the web page containing an embedded applet is viewed in a browser, then the applet code is entirely downloaded in the client's browser. This download time becomes unacceptable when the applet grows in size.

•Applets do not allow performing I0 operation like accessing a file or memory
disks.