There are different types of computer. The largest and most powerful are mainframe computers. Minicomputers are smaller than mainframes but are still very powerful. Microcomputers are small enough to sit on a desk. They are the most common type of computer. They are usually more powerful than minicomputers. Portable computers are smaller than desktops. The largest portable is a laptop. Smaller portables, about the size of a piece of writing paper, are called notebook computers. Subnotebooks are smaller than notebooks. You can hold the smallest computers in one hand. They are called handheld computers or palmtop computers.

The text describes several types of computers, arranged mainly by size and power.

The largest and most powerful computers are mainframe computers. These are used when a very large amount of data must be processed, often by big organizations such as banks, governments, airlines, or large companies.

Minicomputers are smaller than mainframes, but they are still powerful machines. They are not as large or as powerful as mainframes, but they can still handle serious computing tasks.

Microcomputers are small enough to be placed on a desk. They are the most common type of computer. Desktop computers belong to this group. According to the text, microcomputers are usually more powerful than minicomputers.

Portable computers are smaller than desktop computers and can be carried from place to place. The largest type of portable computer is a laptop.

Smaller portable computers, about the size of a sheet of writing paper, are called notebook computers. They are more compact than laptops.

Subnotebooks are even smaller than notebooks. They are designed to be very light and easy to carry.

The smallest computers can be held in one hand. These are called handheld computers or palmtop computers. They are the most compact type mentioned in the text.

So, the order from largest to smallest is: mainframe computers, minicomputers, microcomputers, portable computers, laptops, notebook computers, subnotebooks, and handheld or palmtop computers.