Apple created the ARM-based M-series processors used in modern Mac computers.
Apple silicon is a family of system-on-a-chip processors designed by Apple for its products. The first Mac chip in the M series, the M1, appeared in 2020 as Apple began moving away from Intel processors in the Mac lineup. The transition brought tighter integration between the processor, graphics, memory technologies, and operating system.
The M-series design is based on the ARM instruction-set architecture, but Apple designs its own processor implementations. ARM is therefore not the same thing as Apple silicon. Another common mix-up is calling the M1 a separate computer brand: it is a processor family used inside Macs and some iPad models.