contractor
A person hired to do a specific job for pay.
A contractor is someone hired to do a specific job or project, usually for a set amount of money and time. Unlike an employee who works for a company full-time, a contractor comes in to complete particular work and then moves on.
When your family needs a new roof, they might hire a roofing contractor who brings a crew, installs the roof over a few weeks, gets paid, and leaves. That contractor isn't part of your family and doesn't work for you permanently: they just agreed to complete that one job. Construction contractors build houses, bridges, and schools. But contractors exist in many fields. A school might hire a contractor to fix its computers, or a business might hire a contractor to design a new website.
The word comes from contract, the agreement that spells out what work will be done, how much it costs, and when it should be finished. This contract protects both sides: the contractor knows what's expected and what they'll earn, while the person hiring knows what they'll get and what they'll pay.
Being a contractor offers freedom: you choose which projects to take and can often set your own schedule. But it also means you don't get the steady paycheck and benefits that employees receive. Many skilled workers prefer the variety and independence of contractor work, moving from project to project and building different things for different clients.