Once it was just the gogglebox in the sitting room with a few broadcast channels to choose from and no chance to catch-up on programmes that had been missed. But in the internet age it can be difficult to know what is meant by “television” any more, according to a University of Huddersfield professor whose latest book helps readers reach a clearer understanding of a new landscape in which a huge range of content can be chosen and viewed on a multiplicity of devices.