If the Mac is running macOS High Sierra or earlier, it can run a 32-bit app. If the Mac is running macOS Mojave or later, it can still run a 32-bit app, but only with some additional setup.
Knowing whether your Mac is 32-bit or 64-bit is important as it determines the software that is compatible with it and the maximum amount of memory that can be managed. The three methods mentioned above are easy to follow and provide comprehensive details on the architecture of the processor. If you still can't find the architecture of your Mac, try restarting or using a third-party software like "64Bit Checker."