trade secret

US /ˈtreɪd ˌsiː.krət/
UK /ˈtreɪd ˌsiː.krət/
"trade secret" picture
1.

a secret formula, practice, or process used in a business to give it an advantage over competitors

:
The recipe for their famous sauce is a closely guarded trade secret.
Companies often use non-disclosure agreements to protect their trade secrets.