[Terminology] Sol, gel and gelation
Sol: the solution which colloids dispersing in liquid form. True solution of polymer can also be called sol.
Gelation: sol to gel transforming process.
Gel is a presence status of substance. Gel is semi-solid or solid, and gel is no liquidity.
After remove the liquids, gel becomes dry glue.
Sol which water is dispersion medium is called hydrosol, the corresponding gel is called hydrogel.