A chef is a professional cook and tradesperson who is proficient in all aspects of food preparation, often focusing on a particular cuisine. The word "chef" is derived from the term chef de cuisine (French pronunciation: [ʃɛf də kɥizin]), the director or head of a kitchen. Chefs can receive formal training from an institution, as well as by apprenticing with an experienced chef.

In modern kitchens, chefs often manage both culinary creativity and business operations, including budgeting, inventory systems, and team training.

Different terms use the word chef in their titles and deal with specific areas of food preparation. Examples include the sous-chef, who acts as the second-in-command in a kitchen, and the chef de partie, who handles a specific area of production. The kitchen brigade system is a hierarchy found in restaurants and hotels employing extensive staff, many of which use the word "chef" in their titles. Underneath the chefs are the kitchen assistants. A chef's standard uniform includes a hat (called a toque), neckerchief, double-breasted jacket, apron and sturdy shoes (that may include steel or plastic toe-caps).

The word "chef" is derived (and shortened) from the term chef de cuisine (French pronunciation: [ʃɛf.də.kɥi.zin]), the director or head of a kitchen. (The French word comes from Latin caput (head) and is cognate with English "chief"). In English, the title chef in the culinary arts originated in the haute cuisine of the 19th century. The culinary arts, among other aspects of the French language, introduced French loan words into the English language. The word is often used by itself as an honorific to address chefs by each other, apprentices, and waiting staff.

Various titles, detailed below, are given to those working in a professional kitchen and each can be considered a title for a type of chef. Many of the titles are based on the brigade de cuisine (or brigade system) documented by Auguste Escoffier, while others have a more general meaning depending on the individual kitchen.

Other names include executive chef, chef manager, head chef, and master chef. This person is in charge of all activities related to the kitchen, which usually includes menu creation, management of kitchen staff, ordering and purchasing of inventory, controlling raw material costs and plating design. Chef de cuisine is the traditional French term from which the English word chef is derived. Head chef is often used to designate someone with the same duties as an executive chef, but there is usually someone in charge of a head chef, possibly making the larger executive decisions such as the direction of menu, the final authority in staff management decisions, and so on. This is often the case for executive chefs with multiple restaurants. Involved in checking the sensory evaluation of dishes after preparation and they are well aware of each sensory property of those specific dishes.

In the UK, the title executive chef normally applies to hotels with multiple outlets in the same hotel. Other establishments in the UK tend to use the title head chef.

The sous-chef de cuisine (under-chef of the kitchen) is the second-in-command and direct assistant of the chef de cuisine or head chef. This person may be responsible for scheduling the kitchen staff or substituting when the head chef is absent. Also, the sous-chef will fill in for or assist a chef de partie (line cook) when needed. This person is accountable for the kitchen's inventory, cleanliness, organization, and the continuing training of its entire staff. A sous-chef's duties can also include carrying out the head chef's directives, conducting line checks, and overseeing the timely rotation of all food products. Smaller operations may not have a sous-chef, while larger operations may have more than one.