A computer programmer will choose a symbol to represent each variable used in a program. The computer will then automatically assign a memory location to store the current value of each variable, and use the chosen symbol to identify this location. For example, the letter P might be chosen by a programmer to represent the price of an article. The computer would automatically reserve a memory location with the symbolic address P to store the price being currently processed. Different programming languages place different restrictions on the choice of symbols used to represent variables.
Some languages only allow a single letter followed, where required, by a single number.
Other languages allow a much freer choice, allowing, for example, the use of the full word 'price' to represent the price of an article.