Hooo, boy, I saw this here yesterday and figured it'd be a quick job to answer.
I came back to a pile of bodies.
Anyways, welcome! AskHistorians has a rather strict set of rules to ensure quality, and that might mean a good qualified response might take a bit of time.
In the meanwhile, let me set you up with some quality answers from the past (straight from our lovely FAQ section!) to get you started!
To quickly answer you, the 'pike and shot' era was roughly what we call 'early modern era', a time of incredible social and political, not to mention technological upheaval in Europe (and the rest of the world). I'll let someone with a full set of credentials to go through the details, but check out these posts regardingwarfare at the time.
Here's one by /u/itsalrightwithme detailing what exactly is 'pike and shot'. https://www.reddit.com/r/AskHistorians/comments/330x89/how_were_the_corners_of_musket_protected_from/
Also by him, detailing the famous Swiss pikes. https://www.reddit.com/r/AskHistorians/comments/3y0fbd/how_come_in_history_the_swiss_were_known_for/cy9hmtj/
From /u/WhoH8in and /u/erictotalitarian, here's a good discussion on 'why did people just stand and shoot, are they stupid?' [paraphrased].
If these answer are helping, check out the rest of the collection on this topic here!
https://www.reddit.com/r/AskHistorians/wiki/faq/militaryhistory/earlymodernwar
Cheers.