Scalability is the term we use to describe a system’s ability to cope with increased load. Note, however, that it is not a one-dimensional label that we can attach to a system: it is meaningless to say “X is scalable” or “Y doesn’t scale.” Rather, discussing scalability means considering questions like “If the system grows in a particular way, what are our options for coping with the growth?” and “How can we add computing resources to handle the additional load?”
