What types of mobile computers are there and how are they different?

Laptops, tablet computers, PDAs, communicators, smartphones.
They differ in size and weight, technical capabilities, for example, you can call from a smartphone, but not from a PDA, a laptop can cope with complex tasks much easier than a tablet computer.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.