We have been using a plug-in called WP Super Cache. It needed updating, and I went back and studied the plugin home page for more info.
http://ocaoimh.ie/wp-super-cache/
After perusing it… I realized I had no idea if this plugin would cause us problems with various pages being cached… such as log ins and passwords and other security stuff. And have no real hope of understanding the technical details on this one anytime soon. (this lifetime)
This is the kind of thing that someone like Ed might know about. For now, I decided to deactivate the plug-in… which means, the code for it is removed, and any files it creates on the website are deleted, or moved to a not active location/folder. Supposedly.
Whether this speeds up or slows down… or improves our logins… etc, is unknown at this time, but I hope for the best for our usage comfort.