A Short Tandem Repeat (STR) is a type of genetic marker found in DNA. STRs consist of short sequences of base pairs that are repeated multiple times in a row. The number of repeats can vary among individuals, making STRs useful for genetic profiling and forensic analysis. STRs are commonly used in fields like forensic science and paternity testing. By comparing the number of repeats at specific STR locations, scientists can identify genetic similarities or differences between individuals. This technique is essential for applications such as DNA fingerprinting and genetic diversity studies.