In the old days (of like 24 hours ago) companies like Samsung, Qualcomm and Texas Instruments made ARM chips, while Intel and AMD made x86 based CPUs. Simple. Well not any more. AMD have announced that not only will it make x86 based CPUs but it will now make ARM based chips as well.
ARM based processors, which tech companies license from the British company ARM Holdings, are the most widely used 32-bit CPUs around. They can be found in a whole variety of devices including the majority of Android, Apple and Microsoft based smartphones and tablets.