Working out what the most appropriate Brain (CPU) is for your computer can be very confusing. There is now "Dual" and "Quad" cores and at least six different CPU's to choose from and that is just from Intel.
The good news is that it doesn't have to be confusing!
There are three main chips that you should be considering in a new computer for general use. They are the Intel Core i3, i5 and i7 chips, and they will give you the best chance of enjoying your computer's performance over the next few years.
I like to associate them with cars, so think of them like this:
The i3 is the 4 cylinder, economical machine that will do most things, but its not the fastest.
The i5 is the V6 workhorse that is great for almost everything that requires a bit more power.
The i7 is the V8 or sportscar for those that want to be going at light speed.
With that simple association, you should find it easier to narrow down the choice of what computer to buy based on your particular needs.
There are other chips available, like the Atom, but they should be considered more "specialist" chips as they give extremely good battery life, but at the expense of some performance.
The Pentium and Celeron chips which you might still see around are now the lowest speed computers, and I would not recommend purchasing a new computer based on either of these at this point in their life cycle.
As always, if in doubt, or if you have some special requirements, don't hesitate to ask us!