An unsigned integer is a type of whole number that can only represent non-negative values, meaning it cannot be negative. This is in contrast to signed integers, which can represent both positive and negative numbers. Unsigned integers are commonly used in computer programming and digital systems where negative values are not needed, allowing for a larger range of positive values within the same number of bits. In binary representation, an unsigned integer uses all its bits to represent positive values, effectively doubling the maximum value it can store compared to signed integers. For example, an 8-bit unsigned integer can represent values from 0 to 255, while an 8-bit signed integer can represent values from -128 to 127. This makes unsigned integers particularly useful in applications like memory addressing and counting.