What are liposomes and what are they useful for? (in terms of medicine)

So I'm studying biology and reading about artificially created lipsomes, and the picture shown is an amino acid (glycine) in water and the phospholipid is placed in the water and eventually the phospholipid surrounds the glycine. What is the purpose of this? The question on the side is: What could you put inside these for medical applications and why?

Liposome is basically a sphere of phospholipids. Phospholipids is the stuff that makes up cell membranes. In medicine it is used to transport hydrophobic medical compounds through an aqueous environment and release it inside of a cell. If that medicine didn't have the aid of liposomes, it would dissolve in solution before it ever reached its target. Phospholipids can delivery the medicine without being blocked by the cell membrane because it will fuse with the plasma membrane.

Liposomes provide a means to get charged or polar molecules into cells.

As you know, cells are enclosed in a lipid membrane. Molecules that are soluble in water are generally not also soluble in lipids and so are excluded from cells (unless they are actively transported or unless there is a specific ion pore evolved to allow that particular molecule to pass through). Lipids however can dissolve or mix with the cell membrane easily.

So, by combining the water soluble (polar or charged) molecule with lipids in a liposome, you can encourage the molecule (drug or whatever you put in the liposome) to enter the cell. So, liposomes can be used for drug delivery. They are also useful for delivering DNA (a highly charged molecule) into cells for gene therapy.

The purpose is to protect something that is not water soluble (hydrophobic). You could put all types of medications in liposomes which they are mainly used to administer certain drugs. Because these drugs may not be able to survive or may get denatured in the environment they are put in. So they get put into liposomes which protects them from the surrounding environment.