It is also possible to classify problems on the basis of general techniques or tools needed to solve them. For example, there are a large number of problems that fall into the database category. Examples of databases include a telephone book, a dictionary, and a personal address book. This has led to the development of database software.
Computers are particularly useful in helping to solve database problems.
With database software and telecommunications, some problems that used to be quite complex are now quite simple. For example, an airline has hundreds of flights each day. It must sell tickets for each flight, perhaps for a year into the future. Agencies selling airline tickets are located throughout the world. This ticket sales problem is solved by use of computers, database software, and telecommunications.