I would recommend you read the first paragraph on this site-
An Act of Parliament creates a new law or changes an existing law. An Act is a Bill approved by both the House of Commons and the House of Lords and formally agreed to by the reigning monarch (known as Royal Assent). Once implemented, an Act is law and applies to the UK as a whole or to specific areas of the country.
Regarding Licensing, my understanding over many years was that any DEVICE used to receive TV broadcasts in the UK, from ANY COUNTRY, required a TV Licence.
That is, the TV Licence is for the USE of the DEVICE as others have indicated, not for watching any specific Channel or Programme.
As an extreme example, in the days of Analogue-only TV, occasionally it was possible to receive AUSTRALIAN TV Transmissions in the UK. Even if one only watched that source, no other sources, one still needed within the UK, a UK TV Licence to do so legally.
This activity was informally known as TV-DXing.
The situation was similar for Radio Reception, one may listen only to, say, the Boston Symphony Orchestra playing its Pop Concert series in Boston USA; but still required a WIRELESS Licence to operate a Radio Receiver in the UK, if the receiving/listening was being done in the UK.
Obviously, the situation has changed in recent years as PCs have gained the Internet source for TV; and as TV sets have moved beyond being "simple" TV sets, hence the simplified definition of the DEVICE being used to watch the TV Transmission simultaneously or virtually simultaneously.