There are 2 main manufacturers of processors for personal computers. These are AMD and INTEL.
The basic ranges of processors available are :-
Intel (virtually everything in the Intel range is now dual core)
Celeron – This is an entry level processor often found in cheaper computers. This is designed to compete with the amd sempron ranges. (Now superceeded by celeron dual core)
Pentium 4 – These comes in a series of ranges from entry level to high end processors. Only available in single core.
Pentium D– This is the dual core version of the pentium 4. They are a cheaper version of core 2 duo. Often found in cheaper "dual core" personal computers. Performance is not up to the standards of core 2 duo.
Core 2 duo/Quad – These are the "proper" twin/Quad core processors. These are in tests currently the fastest processors overall. They are significantly more expensive than the pentium D but offer far superior performance.
Xeon – These are Intel’s "Professional" range and like the core 2 come in duo or quad core processors. The overall performance is similar to core 2 duo/quad. They are designed primarily for servers and the Mainboards to run these are considerably (2 to 4 times) more expensive than core 2 mainboard’s. The big advantage over the core 2 however is than you can run several of these on one board. For home computer use where only a single processor is required then core 2 is still the best choice for the price. If however you want to build something to rival the ASCI Red Supercomputer (10,000 Pentium Pro’s running a trillion calculations a second or 1 terra flop) and have a few millions pounds to spend then maybe this is for you.
Intel also produce a range of laptop processors with low power consumption in celeron/pentium and core 2 ranges.
Intel I3,I5,I7 – This Intel range of I processors has now largely been replaced by sandybridge. Some of the I series also have on chip graphics processor. These use new sockets LGA 1156 or LGA1366 and are fabricated on the new 45nm wafers.
Intel I3,I5,I7 (sandybridge) – The new Intel sandybridge range of I processors currently consists of an every growing range. The I series also has on chip graphics processor. These use new sockets LGA 1155 or socket 2011 and are fabricated on the new 32nm or 22nm wafers. The new socket 2011 curerently go up to six core processors.
Future Intel – intel are currently testing an 80 core proof of concept processor which has the ability to run at 1 terra flop. This is the size of an average fingernail and consumes a mere 62 watts of electricity. The ASCI Red Supercomputer with similar performance consumed 500 Kilowatts and took up 2000 square feet!. The new Tylersberg server chipset and nehalem-ep server should be out as you read this.
Sempron – Sempron processors come in either 32 or 64 bit processors and are a cut down version of the amd athlon. They are designed to compete with the Intel Celeron range.
Athlon – Athlon processors come in either 32 or 64 bit processors and dual core varieties. They are designed to compete with the Intel range from the pentium 4 to the pentium d dual core processors. Speed wise they are in tests faster than the intel range in gaming applications. The AMD Quad FX platform is a two-socket, four-core processing solution featuring Dual Socket Direct Connect (DSDC) Architecture for high-bandwidth processor to processor communication.
Opteron – The Opteron comes in a variety of range from single to quad core. They are designed to compete with the intel core 2 duo and xeon ranges. Like the xeon multiple processors can be used on a single board up to a current maximum of 16 cores. In tests they lag behind the Intel range and the high end ones are quiet expensive.
Phenom – The phenom and Phenom2 processors are aimed at high end gamers. they come in dual, triple and quad core versions.
Future AMD – Amd have recently purchased ATI graphics and are working on integrating a cpu and a gpu(graphics processor) on the same chip. This should dramatically increase game performance as the 2 chips can talk to each other at a very fast speed.
Different CPU’s are usually not interchangeable as the manufacturer changes the socket type for each new cpu.