I'm currently in the hiring process with a company based in Switzerland. I will be working remotely from the US but they want me to go to their headquarters to get to know the team/work together/etc.. for only a month. So would I need a Work or Business visa ?
A business visa (type C visa) allows you to enter a country temporarily to conduct business there, such as buying stuff, meeting with collaborators etc. Business visa are usually valid for 90 days, like tourist visas, and they do not allow residence. Whether you actually need to apply to the Swiss embassy in Washington to obtain a business visa depends on your nationality.
A work visa (type D visa) allows you to stay in the country for more than 90 days to conduct business.
See also this FAQ for the difference between the two visas, and for links to the respective applications.