Jay, you question is simple, but maybe people did not give answers in a way you will understand.
Let me explain. You can (theoretically) use 'n' number of amps with the same set of speakers - but individually. That is, at any one time, only one amp can be driving the speaker. There are various ways of doing this.
1. Have two sets of cables running to the speakers, one set from each amp. When you want to listen to Amp A, you connect that to the speakers. When you want to listen to Amp B, you disconnect Amp A first, then connect Amp B. This is the safest and the least expensive way. The 10 seconds you spend in connecting and disconnecting will keep your equipment safe.
2. Connect both amps to the left and right terminals of the speakers. Keep Amp A ON when you are using that, and keep Amp B off. When you want to listen to Amp B, you first switch off Amp A, and then switch on Amp B. If you use good quality banana plugs, you can connect two sets of speaker cables without hassle. BUT, there is an inherent danger in this. If, by mistake, you keep both amps on, you can fry the speakers. Even if you do not keep both amps on, the current from one amp will flow to the speakers and from there to the other amp that is off. An amp's output terminal is designed from flow of current in one way - from the amp outwards. There is no saying what will happen when the current flows from outside into the amp.
3. To avoid these issues, you use what is called a speaker switch. You can connect multiple speakers to the same amp, or multiple amps to the same speakers. You press a button to choose Amp A, or Amp B. The switch ensures that the other circuit is completely cut off.
This is the method used by all professionals.
Do NOT connect both amps to the speakers at the same time. It is dangerous.
Cheers