Eating Ur own dog food :)

I came accross this slang many a times over the last few years. So what does "eating Ur own dog food " mean?

“A company that eats its own dog food sends the message that it
considers its own products the best on the market.”

“This slang was popularized during the dotcom craze when some
companies did not use their own products and thus could "not even eat
their own dog food". An example would've been a software company that
created operating systems but used its competitor's software on its
corporate computers.”