Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Usually used in reference to a computer application, especially a computer game, a text-based application is one whose primary input and output are based on text rather than graphics. This does not mean that text-based applications do not have graphics, just that the graphics are secondary to the text.Before the 1980s, most computers were text-based. The operator used the keyboard as the main input device to type in necessary commands into the terminal that could only display text on a low-resolution monochrome video monitor. The majority of end-user software was also written in text-based mode during this time. During this era, operating a computer was considered to be a challenging task because of the complexity of the text-based environment.