'Press Me'

Copying: Make a perfect copy of an object/replicate it, so you have more than one.
Theft: Steal something. The owner now doesn't have the object, you do.
Piracy: Technically it's copying, but most companies regard it as theft of intellectual property - rather than actual stealing the physical object.

Piracy is in no way new, and the internet is certainly not to blame. Its just progression. Before the internet, people would copy floppy discs/CDROMS. In the UK and Europe before that, you would use 2 tape-recorders and copy the computer tapes so you could have a copy of the latest games. This was rife in the 1980s school, kids sharing games in the school playground. A few pokes into the computers memory, and you had bypassed the primitive security employed, and had a perfect working copy. We were all hackers back then - it was that easy.
Back in the 70s & 80s most record (that's Vinyl!) sleeves had the slogan "Home Taping is Killing Music" - obviously it didn't or the world would be a quieter place today (in some cases not a bad thing).
Even before the digital age, people were copying classic works of art and getting away with it. Every now and then you hear about a painting thought to be worth millions, turning out to be a copy, a fake.

Up until about 10/15 years ago, most computer software was distributed either on floppy disks, or on audio cassette. These don't last forever, due to the fact they use magnetism to store the information on the tape. After time, the tape starts to become more randomly magnetised, and eventually the information contained is lost - or at best unreadable by the computer. Is it still regarded as piracy if you the information from these and make a 1:1 copy to keep, so that it can continue to work? A fine line - some companies don't exist now, but as the software is protected by copyright "its a tricky situation" (Queen - Greatest Hits 1981)