Business strike is a term that distinguishes coins created for commerce from commemorative coins and proof coins. Regular issue coins are normally produced in relatively large numbers, and are primarily meant to be used as pocket change, not collected. Business strike is the technical term for regular issue coinage.
Even though special collector coins, such as proof coinage, are produced in smaller numbers, the regular issue coins are sometimes more valuable in high grade than their proof counterparts. This is because whereas proof coins are almost always carefully preserved by their owners, business strikes usually are not.