Semiconductor fabrication plants are factories where integrated circuits (ICs), also known as microchips, are manufactured. They are either operated by Integrated Device Manufacturers (IDMs) that design and manufacture ICs in-house and may also manufacture designs from design-only, or by pure play foundries that manufacture designs from fabless companies and do not design their own ICs. Some pure play foundries like TSMC offer IC design services, and others, like Samsung, design and manufacture ICs for customers, while also designing, manufacturing and selling their own ICs.