Nina Ricci : Front Row  - Paris Fashion Week Womenswear Fall/Winter 2014-2015
Pascal Le Segretain/Getty Images Entertainment/Getty Images

The fashion terms "collection" and "line" are mistakenly thought to be interchangeable. While both are common terms in the fashion industry, a fashion line refers exclusively to all of the clothing a fashion designer produces for a specific category within her fashion company, while a collection refers to a seasonal production of different styles within a line for that same company.

Collection Within a Line

Collections are found within a line, while a line may be composed of multiple collections. A company may have multiple lines defined by gender, lifestyle or price point while having upwards of eight collections per year per line. Menswear, womenswear and haute couture are considered lines -- the clothing shown in each of these categories during runway shows for a particular season makes up the collection.

Fashion Seasons, Lines and Collections

Every year, a fashion line produces multiple collections related to various seasons. Larger apparel companies often have four or five lines, and each line will have a new collection produced for each season. There are eight seasons in fashion; each season ensures retailers remain stocked year-round with new merchandise. These seasons include Spring and Fall, as well as lesser known seasons such as holiday and resort.