If you are building a system, you’ll want it to be scalable. Ideally, it should be able to accommodate an increase in load with a proportional increase in resources. An example of this is the WhatsApp infrastructure which handles billions of messages every day.
If you are building a company, you’ll want it to be able to grow and scale up quickly as you add more headcount and resources. In theory, given more access to resources, a scalable business will be able to grow it’s revenue and profits proportionally.