The names that you see are code names for that particular chip build. Usually, the names signify how much cache a chip has and the technology it uses such as, 90nm 2X1M cache or 65nm 2X2M cache as examples.
I'm sure someone here can explain it better than I can in case that doesn't make sense to you.
I read about cores of certain chips (i.e. manchester) does this just tell you where the core was made? Does it matter what core you get?
any insight on this matter would be greatly appreciated
Names of the cores are given as an shortened explanation of the specification of that core. They are not named as the area where they are made.
Cores with different names might be different in their architectrure, supported instructions and registers, FSB(know as HTT on AMD K8), manifacturing process, cache memory capacity, levels of cache and etc.
These are code-names to differentiate between different CPU architectures. For example, Conroe is the code-name for Intels up-and-coming Dual-core CPU. Manchester on the other hand, is AMD's current Dual-core CPUs with 2x512KB of cache (The X2 4200, 4600, and maybe the 3800). Toledo on the other hand refers to AMD's dual-cores with 2x1MB of cache (X2 4400, & 4800).
This style is used to help people talk about difference CPUs that are the same, except for the clock speed, without having to actually list each processor model individually.
(Man, I thought you'd beable to find a nice comprehensible list of current code names on the net, but it's not coming up for me).
(edit)Here's a decent list about the different codenames for AMD's current line up of chips.
I noticed that you said that the core name is the code name for the chip, I have everest Trial edition and My chipset is an AMD Athalon. It says that the chip alias is a thoroughbredB is this the same thing?