Multiscreen is a term used to describe a content feature that enables a content to be accessed over multiple screens - smartphones, tablets, TVs, car displays, wearables, laptops, digital signage and computers.
Multiscreen content is enabled by the development of custom applications for each device (in compatibility with the device's operating system) and content adaptation (for example, encoding and bit-rate adaptation) that fit the content to the end-device's screen size and resolution, ensuring optimal delivery of the content.
Web content which is IP based for example, can ony be streamed on a home TV (which does not have a built in operating system such that a computer has) if there is a third party device (a set-top box or a gaming console) that is able to stream this content according to the end-device size and resolution.