B-1/B-2 are Visitor Visas
B1 is a Business Visitor Visa should be applied for at the United States Embassy/Consulate Abroad when you want to come to the United States to meet with business associates; to sell or buy properties,equipment etc;to negotiate contracts;and, for business conventions and seminars. B1 may be used by personal and domestic employees of their U.S citizen based abroad if they are accompanying the employer to the United State. It is also available to employees of foreign citizen employer who is in the United States on a non-immigrant visa.
B2 is meant for pleasure(to visit friends,family etc ), tourism(to visit Disney Land,Dallas Arboretum etc), to partake in musical and sports events at amateur with no income, and, for medical treatment in the United States.
United States exempts citizens of certain countries from obtaining these types of visa when coming to United States for those purposes ie, Canada. The visas are also waived for citizens of certain countries ie United Kingdom, Germany, Belgium, France, Republic of Island, Italy etc.