Java
Do I need Java on my iMac?
iMac, OS X El Capitan (10.11.3)
Do I need Java on my iMac?
iMac, OS X El Capitan (10.11.3)
There are two uses for Java - to support applications which run on it, and to act as a plug-in in your browser for websites which use it.
In the former case, you need install it only if you have one of the rare applications which requires it. There is no security problem about doing this.
However in the case of the plug-in for a browser, you should be cautious about this. Few websites now use it (indeed I don't have it installed for the browsers and I can't think of any website which uses it other than one page on my own), and it is a considerable security risk: of you really must use it you should only enable it when required. Note that we are talking about Java, not Javascript - the latter is quite different and should be left enabled as many websites won't work without it.
Not unless there is a specific application you need to run that requires it, no.
Java