A General is an officer of high military rank. The term or equivalent is used by nearly every country in the world. General can be used as a generic term for all grades of general officer, or it can specifically refer to a single rank that is just called General.
The various grades of General Officer are at the top of the rank structure; lower-ranking officers are known as field officers. The General Officer ranks came about by adding General as an adjective to existing names of ranks, although in some countries the highest General Officers are titled Field Marshal or Marshal. All officers who commanded more than a single regiment (the most significant level of unit) came to be known as "General Officers".