Random-access-memory (RAM) is the short term memory for your computer. It stores data that your system needs to access on short notice. Your operating system and your programs are loaded into the RAM.
Anno 2015 8 GB of DDR3 1600 MHz is the bare minimum the keep up with the latest technology development. For desktop computers I would recommend 16 GB, while this amount of RAM might be overkill you will likely never run out of RAM.
If your computer still runs on 2 or 4 GB I would highly recommend you buy some new RAM sticks this will boost your computers responsiveness.
Central Processing Unit (CPU) is the brain of the computer. CPU’s are available in dual, quad and octa core. In general the more cores you have the better. However most programs don’t utilize more than four cores.
Get a fast quad core Intel Core I5/ I7 (Sky lake) or an AMD (Zen) processor for the best experience.
HDD / SSD Hard Disk
A hard disk is the long term memory of your computer
HDD’s are mechanical drives and can store up to 8 GB per drive although typically the storage capacity of a HDD is somewhere between 500 and 2000 GB. HDD’s have high storage capacity but are slower than SSD’s.
SSD’s are blazing fast and in some cases can be more than 10 times as fast as mechanical HDD’s. They are expensive but add great value to your user experience.
Laptop vs. Desktop
Desktop PC’s always outrun laptops. Even a 100$ AMD budget quad core will outrun any expensive laptop core I7 processor. If you have the choice between desktop and laptop always choose a desktop PC, they are not limited to thermal or power limits.
Laptop are available as cheap as 200$ however I would never recommend buying a cheap laptop, often they are composed of the worst components available and are slow out of the box. Often you will need to buy a new one in about two years. I would never recommend a laptop or desktop PC under 500$, the more expensive the computer is the longer it will last.
Our 2011 office computer cost around 1000$ but is still up to date today and outruns any laptop available today.
Summarized: Don't get a cheap computer it will cost you more in the end.