What is the purpose of a cisco stack as apposed to just adding individual switches?

A few years back I had to fly to a remote data center and was sent several cisco switches that were to be "stacked" I recall unboxing everything and plugging it all in via instructions from my home office. I booted with a console cable and configured the initial IP address. Then home office pretty much took over and although I was able to observe a lot if it did not sink in. I do recall the stacks only had 1 IP address each and since it was a remote data center we had set up switch redundancy. I remember plugging in cables that had to be crossed to the switch below and when it was all done everything was set with dual power supply and I could have sworn it was configured so if a switch failed another one would take over. I had another job after that where a cisco stack was already installed. I recall 5 switches and when we had to shut down power the Master had to do go down last and come up first. At least I think that was the order, it was written on the wall next to the devices. I am asking all this because I have a job interview that will including installing and initializing a lot if Cisco devices including stacks. It sounds like it will be very similar to what I did years ago, installing the hardware and getting it set so the engineers in the home office could take over. I just do not remember the purposes for a stack as apposed to multiple switches. I know you will save IPs by configuring a switch as a stack, but what the other main reasons? I know the remote install from years ago included redundancy and cables were connected in a specific manner. For redundancy do you need two specific stacks and if one fails the other takes over or does a single stack offer redundancy? Most of the jobs I have done recently involved small offices and I just added another switch with another IP address if more ports were needed. All advice welcome