Don't panic! AOSC OS comes in a variety of flavors, with multiple architectures supported. However, we (tried to) believe they are quite logically arranged according to:
So what are all that you just listed then? Let me finish...
AOSC OS provides different variants based on different desktop environments provided, and what they are used for (in the case of BuildKit, a specialized as a minimal development environment for quick deployment). As what AOSC OS is designed as, usually people will go with a variant with desktop environment with full desktop environments. For lower performance (older PCs), semi-embedded (yeah that doesn't count...) systems like a Intel NUC, or boards like a Raspberry Pi, you might want to go with the "Base" variant - which has no desktop environment pre-installed, and comes with the least amount of packages to get you started (keep that happy hacking on).
AOSC OS is not only available for AMD64. ARMv7, ARMv8, and MIPS (more to come!) are all under our sphere of influence (fear us). Only the "Base" and "BuildKit" variant comes in multiple architectures, variants with desktop environments are currently only available to AMD64 users.
AOSC OS is available in multiple media types:
For more detailed installation instructions, please move over to our Wiki.