The viral envelope contains glycoproteins that are used to bind to host cells. Viruses with envelopes produce diseases such as chicken pox, influenza, and mumps. Due to the fragility of the envelope, non-enclosed viruses are more resistant to temperature, pH, and certain disinfectants than enveloped viruses.
A capsid is a protective coating of proteins that surrounds the nucleic acid genome of all virions. Some viral capsids have a simple polyhedral "sphere" structure, whereas others have a more complicated shape.