A trade secret is a pattern, formula, process, design, instrument, not generally known and which a company or organization uses to gain an advantage over competitors or customers. As the name implies, it is a secret information with which organizations operate and should be kept secret.
It is not for the general public to know, and reasonable efforts are made to maintain its secrecy. For instance, in some organizations, only employees in certain distinct positions know its trade secret and are prohibited to disclose it.
A trade secret is not only for organizations. Individuals who run a small business can have their own trade secret which should be guarded like any other secret. Your trade secret is what makes you stand out, it is wise to guard it jealously.