You have to arrange an account with an ISP to get broadband access - the ISP, with BT, activates the line for you. There are zillions to choose from, have a look here as a good start: click here.
A hotspot is the area in which your wifi card can pick up a signal. If you're lucky, one of your neighbours might have an unsecured network that you could piggyback on but that's not exactly best practice.
You often see coffee shops etc saying they have hotspots: the idea is the same, in other words it's an area covered by the signal broadcast by a wifi router. But coffee shops will ask you for money to connect to their network.
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