There are various kind of sealants available used for different purposes. Silicon sealant is mainly for windows frames.
Many home owners mistaken M-seal as sealant. M-seal is similar to EPOXY a waterproofing agent that is usually of 2 component. Whereas silicon sealant is a single component sealant in semi-solid form.

There are branded and non-branded silicon sealant available in market. It is not typically box packed sealant/product. Silicon sealant is available like a gun. On pressing one end, the sealant rolls out for application.

Usually the affected area is given a cut or grooved where, then, silicon sealant is applied. Many a times it is used in kitchen sink area, mainly where the outlet pipe joint.

What is Expansion Joint?

Expansion joint is a joint created between 2 buildings. Let’s say 2 building need a joint that lie nest to each other. But this is not done as it isn’t possible and a gap of 50 mm (assume) is given. To seal this gap a different types of sealant is used. This joint created is called as expansion joint.

Such joints or Sealants are in heavy duty areas like bridges, joints of railway track, etc. the sealant used is a 2 component poly-sulphite sealant. This is used in similar way as M-seal i.e. the 2 component are mixed with each other and applied where necessary.