The discussion is very simplified and only intended to give the reader a basis to understand the web sites listed on the geological mapping page. In its loosest sense a database is any accumulation of information.
Electronic databases adhere to much stricker definitions.
The best way to think of a database is as a set of 3x5 index cards. Suppose you wanted to make a list of different kinds of mines. Although the details are different from computer program to program, a computer database table usually consists of a series of these records headed by an information table detailing how the information is to be read by the computer. The differences between the formats adopted by different computer programs makes it difficult for one program to read data compiled in another. However there are certain formats that all computer programs can read.