There are many computers in a server rack. Generally there are between 15 and 100 computers on a server rack depending on the size of the business and or building.
If you mean processing cores (the brain of the computer that makes everything talk to eachother) it depends on the computer. Most have one or 2, the higher end computers have 4 to 8. Super fast...
Server Computer is the head of all the network computers that called as a client computer. Server computer main duty is the main storage of all the data of the client computers. Also, Server computer...