The access gap is about getting online at all: having a device, a connection, and being able to afford both.
The usage gap is what comes after getting online: being able to do what you need, and to judge what you see.
The gender gap is about who gets online, who builds the technology, and who gets targeted on it.
The generation gap is about age: who grew up with digital technology, and who's had to pick it up along the way, often with little support.
Disabled people are often shut out by design: websites, apps, and services built without them in mind.