What are the concepts of osmosis, osmotic pressure, osmolarity and tonicity?

I share the link of my channel. / @mauriciogiuliodori
The concepts of osmosis, osmotic pressure, osmolarity and tonicity are described, which are often used as synonyms and in reality they are not. Isoosmolar, hypoosmolar and hyperosmolar solutions are described. Isotonic, hypotonic, and hypertonic saline solutions are described.