Here are four characteristics of a computer:

1. Speed
   Computers can perform operations at incredible speeds, far exceeding human capabilities. They are measured in Hertz, and can perform millions or even billions of calculations per second.
2. Accuracy
   Computers are highly accurate and consistent, provided they are given the correct input and instructions. Errors are usually due to human error, incorrect data, or faulty programming.
3. Storage Capacity
   Computers can store vast amounts of data and information. This allows users to keep large files, programs, and operating systems on the machine for later use. Storage is measured in bytes.
4. Automation
   Once a computer is given a program or set of instructions, it can perform the task automatically without human intervention. This automation reduces the need for manual labor and allows for efficient processing of repetitive tasks.