proprietary

What does "proprietary" mean in the following?

In the early 1990s, IBM had a clear mission and vision as a proprietary hardware company. But Louis Gerstner altered both dramatically by switching to intergrated services.

Dies it mean IBM produces and sells only hardware?

Thank you.

No, but it means that they owned it and only licensed it, I think, but I don't get why they are described as a hardware company that late- they were making software too. Nowadays, IBM has moved much more towards the open source area of IT. And they had licensed the manufacture of PC clones of their architecture long before that. It might make sense to a specialist, but it doesn't to me.

When IBM made the original PC, it was copied by many "clone" makers. That all these clones functioned the same and ran the same software helped consumers greatly, but it was IBM that saw its market share dwindle.

They wanted to return to a proprietary model, like Apple. Apple doesn't open up its designs and allow others to make compatible computers.