The difference between integer and floating-point data types in programming lies primarily in their representation of numbers. Integers represent whole numbers without decimal points, making them suitable for counting and indexing. In contrast, floating-point types allow for the representation of real numbers, including fractions, by using a decimal point. This distinction leads to differences in memory usage and precision; while integers provide exact values, floating-point types can introduce rounding errors. Understanding these data types is crucial for selecting the appropriate type for specific computational tasks.