Useful to know:
RTW (also known as “pret-a-porter”) stands for ready-to-wear and it encompasses designers’ main collections: spring-summer (S/S) and fall-winter (F/W) or autumn-winter. Spring-summer collections are shown in September and mark the beginning of the new fashion year, and fall-winter collections are shown the following February.
Resort (or “cruise”) is shown in May to early June and has traditionally been for wealthier customers who desire to escape to warmer climates during the colder seasons. The clothes are often lighter and more colourful and there’s heaps of swimwear. Most designers opt for lookbooks and presentations rather than a full-on runway show (except maybe Chanel). Resort collections arrive in store in November, just after the fall-winter clothes in September but before the spring-summer arrival in March and April the following year.
Pre-fall is shown between December to January, is a little more vague. They exist to bridge the gap between the S/S and F/W collections in a more casual environment and are much more commercially driven. They arrive in stores in May when the spring clothes from the previous year are being reduced, and the fall clothes which arrive in September are still being manufactured. Pre-fall also offers the fashion media a chance to see designers’ influences for the coming F/W collections.
Haute Couture is shown twice a year in January (spring couture) and July (fall couture). Unlike ready-to-wear, which is made in standard sizes, couture is made for a unique client and the garments can cost more than your house. Designers can do things with couture that they can’t do with ready-to-wear because then the prices get too expensive. A real couture house is approved and regulated by the Chambre Syndicale in Paris.
Note: Juicy Couture is not a couture house.
(From katemess on tumblr, edited slightly for formatting)