Silicone is a structural adhesive that can give you an elastic seal or an elastic bond, respectively. Silicones are based on different oxygen chains. The characteristic of silicone is that all types are extremely resistant to UV radiation and chemical influences from e.g. oils or the like. They also have a high temperature resistance.
A silicone can be either 1 component or 2 component. It cures either by absorbing moisture when mixed with a hardener (2 component version), by heat and some by using UV light.
In the industry, silicone has many different uses. The reason for this is among other things. in that, with proper choice of silicone, the material elasticity can be precisely what is required for the given purpose.
Silicone can be used for e.g. encapsulation or sealing of electrical components, gasket or for general joining, where items are either exposed to high temperature or must have a high elasticity.