Which of the following describes pili?

Pili, often referred to as fimbriae, are indeed short, hairlike protein structures that extend from the surface of certain bacterial cells. They are primarily involved in attachment processes, allowing bacteria to adhere to surfaces, other cells, or even to each other, which can be critical for colonization and infection. Unlike flagella, which are longer and whip-like and enable movement, pili are shorter and play significant roles in bacterial adherence and motility. This distinction is essential in understanding the structure and function of bacteria in microbiology. Their composition typically involves proteins called pilins, which assemble to form these structures. The other options describe different features or components that do not accurately capture the characteristics or functions of pili.