The expression "i=7" indicates that the variable i is assigned the value of 7. In programming and mathematics, variables are used to store data that can change or be manipulated. Here, i is simply a placeholder that now represents the number 7. In this context, i could be used in various calculations or functions. For example, if you were to add 3 to i, the result would be 10, since 7 + 3 equals 10. This assignment is a fundamental concept in programming languages like Python or Java, where variables are essential for creating dynamic and functional code.