Architecture and microarchitecture
Beginner
The overall plan of a chip: which big parts it has, what each one does, and how they connect.
Novice
Architecture is the chip-level plan: which big blocks the chip has (processors, special-purpose units, memories, the connections between them) and how they work together. Microarchitecture is how one block is organized inside, for example how many steps a processor splits each instruction into and how big its caches are.
Expert
The word is used two ways. In processor design, “architecture” often means the instruction set, the list of instructions software can use, and “microarchitecture” is the hardware that carries them out. In chip (SoC) design, “architecture” means the plan the RTL team implements: the block partition, memory system, interconnect, clock and power plan, and per-block budgets.