"There's an Ericson file in there, Somewhere... !"
"ZIP" refers a common type of file compression software. It makes the file smaller for faster upload and download for us end users. It also helps to protect the information in the file, to some extent, as I understand things, from data corruption on its way through the wilds of the internet.
Any Windows or Mac or Linux computer should be able to "expand" any zip'd file with a free expansion utility. If you are using a library computer, they may have some restrictions on accepting compressed files due to (valid) fears of bringing viri if they are using the Windoz OS, and general concerns about enabling piracy and porn no matter what OS they use. Ask the librarian for assistance, is what I'd do.
Second part of the answer: after you uncompress the file, you need the free reader application from Adobe, "Accrobat Reader" to view/copy/print the file. That should also be present on the computer you are using, IMO.
All the Best,
Loren