Thanks, glenster, tirebiter, caa, villagegirl and Apognophos!
Your comments and direction help a lot.
Villagegirl: I don't know how to answer all your questions. Yes, iMacs appear free from what plagues pcs. The old desktop I'm on now has safeguards that appear regularly to alert me. The 10-year-old iMac laptop given me (the object of this thread) had not been cleaned up of the former owner's stuff; as a result, it was difficult to operate in an optimum manner because, on delivery, I was given no passwords. All procedures were blocked as a result. No updates and regular check-ups made it vulnerable, I'm surmising.
Thanks for all your input!
CC