The instruction "ADD A, 5" is a simple command used in programming and assembly language. It tells the computer to take the value stored in the variable or register A and add the number 5 to it. The result is then typically stored back in A, updating its value. This operation is part of basic arithmetic in computing, which is essential for performing calculations and manipulating data. Understanding such commands is fundamental for anyone learning about computer programming or assembly language, as they form the building blocks of more complex operations.