If you plan to visit the USA for a holiday, business or family visit you need a visitor (B) visa. There are 4 categories of this visa:
Visitor visa allows you to travel to the USA for purpose of business, participation in meetings and conferences as well as for tourist visit, family and friends visit or medical care and treatment purposes. You are not allowed to work or study during your visit except in special cases with B-1 visa as self-employed.
Visitor visa is being issued on a period of 10 years, and a length of one stay can be up to 6 months.
Application for visitor visa is going through American embassy in your country. One of the steps in the process is interview in consular section.
Visa fee for visitor visa application is 160USD and a processing time depends on the case. The waiting period is the time until your scheduled interview. In certain cases, after the interview the officer could require additional processing that could last up to 6 months.