Before I get into the details, a quick recap of processors is necessary. Be aware that the price of a laptop (along with screen size) is determined by the processor (cpu). 

The two main CPU companies are Intel and Pen Drive Price in Bangladesh AMD (there's also Apple, but let's stick to mainstream laptops). Intel makes the famous line of Pentium processors (''Intel inside'' ting tong ting tong!). 

For laptops, you have three main processors - the Mobile Pentium 4 (essentially a P4 desktop processor), the Pentium M (a low-voltage processor that extends battery life and is specifically made for laptops), and the Mobile Celeron processor (the poor man's P4 cpu). Wait, you say, you didn't mention the Centrino processor. 

That's because Centrino isn't a processor – it's technology. Centrino is a combination of 3 things - Pentium M cpu + 855 chipset + Wireless Pro (802.11b). Another company is AMD - they make really good processors that compete with Intel processors.

AMD CPUs have traditionally had issues with heat generation, but there haven't been many complaints recently. I would suggest you stick with Intel processors which have good resale value.

The next question is....what will you be using the laptop for? Will you be using it for simple things - spreadsheets/word editor/internet browsing? Then go for a Celeron CPU. If you are going to do more serious work with your computer, intend to travel often and want to run your laptop on battery power, choose a Pentium M laptop.