Database normalisation
A traditional alternative is the "flat file database", where all of the data is grouped together like in a spreadsheet. The problem with flat file databases is that they can have a lot of blank spaces and there is a lot of information that has to be repeated for each entry. This means that the database is bigger than it has to be, and it makes it more likely that the database will contain mistakes. Relational databases, by breaking the data into groups, reduce the chance of mistakes happening and does not take up any more space than necessary. But for it to work it needs to be well designed.