The B-1 visa is  a nonimmigrant visa that allows foreign nationals to enter into the U.S. temporarily for certain business-related activities. However, it does not broadly permit employment or labor for a U.S. company. Business visitors on a B-1 visa may engage in activities, for example, attending meetings, negotiating contracts, consulting with business associates, participating in short-term training, or attending both conferences as well as conventions. 

In addition, they may settle estates and conduct some professional services that do not involve directly employed in the U.S. For B-1 visas, people must demonstrate that their stay is short, pay for themselves during the visit, and that they will eventually go back to their home nation. 
The usual length of any stay is for up to six months, with some possible extensions in specific circumstances. However, engaging in any forbidden employment while on a B-1 visa can result in certain visa violations and potential bars from reentry. More details on eligibility and permitted activities can be found on the USCIS website.