"Data gravity is a metaphor introduced into the IT lexicon by a software engineer named Dave McCrory in a 2010 blog post. The idea is that data and applications are attracted to each other, similar to the attraction between objects that is explained by the Law of Gravity. In the current Enterprise Data Analytics context, as datasets grow larger and larger, they become harder and harder to move. So, the data stays put. It’s the gravity — and other things that are attracted to the data, like applications and processing power — that moves to where the data resides."

https://www.cio.com/article/3331604/data-gravity-and-what-it...

it's the concept that data are difficult to move and attract the code to it. Generally used, in the large to describe things like AWS S3 attracting AWS to build services on top of it. But I think it's true in the small, too like "frameworks on top of each person's browser data".