On Thursday, we’ll finally get a sense of the true scope of one of the most important businesses for the Internet.

Amazon is due to announce the size of its Web Services product. Amazon Web Services (AWS) is a set of cloud services often used by startups, big companies, and government agencies. You might know AWS better as “the servers that run Netflix and Instagram.”

AWS lets companies buy powerful computers cheaply and whenever they need them to handle traffic, to store video, to power a database. It’s not an understatement to say that AWS is the piece of infrastructure that has enabled the current tech boom. The only single technology which might come close to it is the smartphone.

Why? The 2010s tech industry is built on quickly scaling a product to as many users as possible. It’s based, on other words, on fast growth. AWS and its competitors are what permit that fast growth. They have taken the normally considerable equipment costs—of servers, cables, hard drives, and power supplies—and abstracted them away. Entrepreneurs and coders can think about and purchase computing power on an as-needed basis, while the physical data centers they’re actually using sit far away in Virginia or Oregon.