The most important thing about a visa is its intent.
The B1 visa is said to be for business and B2 for pleasure. However, they are often used interchangeably. The intent of both of the visas is to visit the country on a short-term basis and then return to your mother country. However, you can remain in the country for up to one year.
Keep in mind; there are a variety of things you simply can’t do while you are in the US with certain visas. For the B1/B2 visa, you can’t do the following:
- Perform as an entertainer or participate in professional sports
- Attend college
- Work for gainful employment
Based on that last point, freelancing would fall into the “against the rules” category.