A salad is a dish consisting of a mixture of small pieces of food, usually vegetables or fruit. However, different varieties of salad may contain virtually any type of ready-to-eat food. Salads are typically served at room temperature or chilled, with notable exceptions such as south German potato salad which can be served warm.
Garden salads use a base of leafy greens such as lettuce, arugula/rocket, kale or spinach; they are common enough that the word salad alone often refers specifically to garden salads. Other types include bean salad, tuna salad, fattoush, Greek salad (vegetable-based, but without leafy greens), and somen salad (a noodle-based salad). The sauce used to flavor a salad is commonly called a salad dressing; most salad dressings are based on either a mixture of oil and vinegar or a fermented milk product like kefir.
The Romans, ancient Greeks and Persians ate mixed greens with dressing, a type of mixed salad. Salads, including layered and dressed salads, have been popular in Europe since the Greek and Roman imperial expansions. In his 1699 book, Acetaria: A Discourse on Sallets, John Evelyn attempted with little success to encourage his fellow Britons to eat fresh salad greens. Mary, Queen of Scots, ate boiled celery root over greens covered with creamy mustard dressing, truffles, chervil, and slices of hard-boiled eggs.
Salads may be sold in supermarkets, at restaurants and at fast food chains. In the United States, restaurants will often have a "salad bar" with salad-making ingredients, which the customers will use to put together their salad. Salad restaurants were earning more than $300 million in 2014. At-home salad consumption in the 2010s was rising but moving away from fresh-chopped lettuce and toward bagged greens and salad kits, with bag sales expected to reach $7 billion per year.
A green salad or garden salad is most often composed of leafy vegetables such as lettuce varieties, spinach, or rocket (arugula). If non-greens make up a large portion of the salad it may be called a vegetable salad instead of a green salad. Common raw vegetables (in the culinary sense) used in a salad include cucumbers, peppers, tomatoes, onions, carrots, celery, radishes, mushrooms, avocado, olives, artichoke hearts, heart of palm, watercress, parsley, garden beets, and green beans. Nuts, berries, seeds, and flowers are less common components. Hard-boiled eggs, bacon, shrimp, and cheeses may be used as garnishes, but large amounts of animal based foods would be more likely in a dinner salad.
In the United States, mayonnaise-based ranch dressing is most popular, with vinaigrettes and Caesar-style dressing following close behind. Traditional dressings in France are vinaigrettes, typically mustard-based, while sour cream (smetana) and mayonnaise are predominant in eastern European countries and Russia. In Denmark, dressings are often based on creme fraiche. In southern Europe and the eastern Mediterranean, salad is generally dressed by the diner with olive oil and vinegar. In Asia, it is common to add sesame oil, fish sauce, citrus juice, or soy sauce to salad dressings. Other condiments sometimes used as salad dressing include lemon juice, lime juice, and pumpkin seed oil.