Cisco and many other Network companies, like HP use PowerPC processors in their layer 2 and layer 3 switches. Newer versions like the Cisco 2960X switch uses an APM86392 600MHz dual core by AppliedMicro. This processor has been used for many of the new switch series in different varities.
The larger and more hardcore layer 2/3 switches/routers uses the new Cavium 6230 800 MHz 4-core CPU, like the 3650 and 3850 series.
When you change to data center switches, the CPU is typically an Intel(R) Xeon(R) CPU. This is normally on the Nexus series. The Cisco ASR 9000 Series Aggregation Services Routers uses an RSP processor. The RSP880 has 8 cores, 1.9 GHz while RSP880-LT has 4 cores, 2.4Ghz.
I've probably forgotten a lot, but there's a big difference in CPU's depending on what the purpose of the switch or router is. Also, like the consumer market, CPU's for the commercial market is constantly being upgraded. A change in the CPU architecture takes time and therefore sometimes the same CPU will be used for generations.
In Cisco, to find out what your switch or router CPU is, you can search for the Data Sheet on google for your specific model. If you have CLI access typically
show version will give you information about the CPU on the switch or router.