Products that effectively interact or transfer information between each other are compatible. A computer and a printer are compatible if information transferred between them results in a correctly printed page. Databases are said to be compatible if they can read each other's files. Products are also said to be compatible if they work within a particular computer system. Software is called Microsoft Windows compatible if it can work within the Microsoft Windows environment. Finally, products are called compatible if they can be substituted for other products—i.e., a personal computer is called IBM-PC compatible if it can run the same software as a brand-name IBM-PC.