Since in UKM (near to end of the graduation), I have started freelance jobs. Starting with team up with friends, small project until I have big / enterprise size of application need to develop.
So, making business in IT, is challenging, and you not only need to foreseen what's for you, but for your client too.
Solving the client problem is number 1 priority, but making profit is also priority.
Business, teach a lot of things - learn how to communicate, how to be tolerate, how to manage your team members, and a lot more.
For this skill, I have a lot to learn.