Project signature in android studio?

Question

Android

There are a couple of questions about signing android projects: let's say you created a key, signed an application with it, should the signature of the next version be the same key? What edits are needed in the code (version code/app)? When signing another project, use the same key with different alies? Should the company name in the project path and key(com.name...) match? And then I’m already sitting for the second day, I’m suffering with signatures - I signed it, installed it, but didn’t install the next version, signed with the same key (an error, the program exists), I deleted the program (completely). It doesn’t sign, it doesn’t immediately install ...

Answer 1

1) The signature of the next version must be the same key with the same alias
2) You don't have to make changes in the code for the next version, the main thing is that the number should differ upwards. If anything - googleplay will tell you
3) When signing another project, you can use another key (not sure), and the same one with the same alias (100%)
4) company name may not match