I don't know how things work in the UK, but here in the states various bills/acts are often given misleading names because politics. In this case, "right to work" means, basically, the right to take a job without either having to join a union or being prohibited from joining a union.

There's debate over what the impact of "right to work" is, and of course, what role unions should play.

Another term that might interest you is "at will employment". This one means that your employer can fire you at any time for any reason that isn't illegal; and, you can leave your employer at any time for any reason that isn't illegal. This one is also argued intensely as to whether it is more favorable to the employer, employee, or neither.