Scalability refers to the capability of a system, network, or process to handle a growing amount of work or its potential to be enlarged to accommodate that growth. A scalable system can maintain or even improve performance and security as the size of the system increases. Other options, such as adaptability and flexibility, may be components of a scalable system, but they do not directly define the system's ability to grow. Durability refers to the system's ability to withstand wear, pressure, or damage, which does not directly relate to scalability.