What are the words for Eternal in the Bible?

I have heard that aidios is the only word for eternal and all others are only referring to age (an ending period of time). (Possible source link added ) In the Bible Aidios is used only twice in Romans 1:20 and Jude 1:6-7. There are several other words, but I'm not familiar with them. Can someone please give me an short overview of the various words for Eternal, age, and similar? I am primarily interested in the true words for "eternal" and not "age".