Mr. Davidoff's response is spot on. The general relationship is the greater the number of allowances you claim, the less tax withheld. Ideally you want the amount withheld to be as close as possible to your actual tax liability. If you withhold too little, you must pay, and in some cases, would incur a penalty.
For the county in southeastern Missouri, see Butler County, Missouri. Butler is a city in Bates County, Missouri, United States. The population was 4,219 at the 2010 census. The county seat of Bates County, the city is named for William Orlando Butler, a noted American military and political figure of the early and mid-19th century. It is located approximately fifty miles south of Kansas City, Missouri on U.S. Route 71-Interstate 49.
Butler, New Jersey. Butler is a borough in Morris County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 7,539, reflecting an increase of 119 (+1.6%) from the 7,420 counted in the 2000 Census, which had in turn increased by 28 (+0.4%) from the 7,392 counted in the 1990 Census.