When to use teflon tape and when to use joint compound?

Teflon tape is used for sealing threaded connections in Plumbing applications, particularly with metal pipes and fittings, to prevent leaks by providing a tight seal. Joint compound, on the other hand, is best used for sealing joints and gaps in drywall or plaster, as it provides a smooth finish and is suitable for painting. Use Teflon tape for water or gas lines and joint compound for drywall finishing. Avoid using joint compound on plumbing connections, as it is not designed for that purpose.