Usually, if a unit of a business can be carved out of the entire company and remain self-sufficient, it may be classified as its own segment. A business segment is a portion of a business that generates revenue from selling a product or a line of products, or by providing a service that is separate from the primary line of focus for the business.

At my job, we sometimes mix definitions when referring to Line of Business (LOB) versus Business Segment, so I wanted to get some clarity on the difference between the two. Typically also referred to as a business unit, a business segment is generally a major division in a large corporation.