Yes and no. It is another job, in the sense that someone is compensating you for the provision of a service. But it is not just another job in the sense that you are in full control of what you do and don't do. If you want to scale back your freelancing hours so that you can spend more time on your speculative business ventures, you can. And if you want to increase your hours because Christmas is coming up and you could do with some more money, you can do that too.
Not only that, freelance work will set you up with invaluable contacts. If you decide in the future to move on from freelancing, you will come out the other side with a highly-developed skill, a reputation, and a platform with which to base your business upon.