KeepItMobile,
BYOD is access to company information, just on an end-user's device. The simplest and most common use is user access to email. If the company does not have to deploy a laptop or phone to every one of their remote workers that requires email, they can promote access to information and save money on hardware costs at the same time.
Most email these days is accessible on any phone platform. In addition, many companies have made their applications web-based, because it is supported on many more platforms and it is possible to deploy them without having to maintain thick clients on their customer or employee devices. BYOD is simply an extension of this idea, but without the requirement of using company hardware.
If a company is not providing access to its information leveraging as many platforms as possible, from as many locations as possible to its employees, customers and partners, you have to wonder if that company is being as competitive as it can be.