Thermal pastes are applied between two components (e.g. integrated circuit and heat sink) without a curing process to eliminate air gaps and maximise heat dissipation.
Because thermal paste does not cure, it is only used in applications where the viscosity of the paste allows it to stay in position. E.g. in electronics.
Thermal paste does not mechanically bond (glue) the components together, while thermal adhesive does.
Phase-Change Materials (PCM) are also typically used in place of thermal paste.