A guild was an association of craft and industry.

Explanation:
- A guild was a medieval association of craftsmen or merchants who came together to protect their common interests and regulate their trade or industry.
- Guilds played a significant role in medieval society, particularly during the period of the High Middle Ages (11th to 13th centuries) and the Late Middle Ages (14th and 15th centuries).
- Guilds were formed by individuals who practiced the same trade or craft, such as blacksmiths, weavers, carpenters, and bakers.
- The primary purpose of guilds was to ensure quality control, maintain standards, and protect the interests of its members.
- Guilds regulated the training and apprenticeship of new members, set standards for the production of goods, and established rules for pricing and selling products.
- Guilds also provided social support for their members, including healthcare, pensions, and assistance for families of deceased members.
- Guilds often had their own halls, where members could meet, discuss matters related to their trade, and socialize.
- Guilds were hierarchical in nature, with apprentices, journeymen, and masters. Apprentices would learn the trade under the guidance of a master, and once they completed their training, they could become journeymen. Journeymen would work for a master, gaining experience, before eventually becoming masters themselves.
- Guilds had their own rules and regulations, known as "guild regulations" or "guild statutes," which governed the conduct of members, the quality of work, and the relationships between masters and apprentices.
- Guilds also had their own symbols and emblems, which were used to mark goods produced by guild members, indicating their quality and authenticity.
- The decline of guilds began with the emergence of the modern industrial system, which led to the formation of trade unions and the liberalization of trade and industry.

In conclusion, a guild was an association of craft and industry formed by individuals who practiced the same trade or craft. Guilds played a vital role in medieval society, regulating trade, maintaining standards, and protecting the interests of their members.