Masturbation is an act of giving self pleasure or sexual pleasure this is done by everyone. This involves stimulating and exploring one's own body through various techniques to experience sexual arousal and pleasure.
Masturbation helps an individual understand their body and erogenous parts of their body through exploration in a fun and healthy manner. Some of the techniques involved are touching, rubbing, use of a sex toy, or use various objects available such as hand shower, faucet, pillow, ice, among other things.
Masturbation can just involves the genitals or it can involve other parts of the body. Every individual experiences pleasure differently and hence knowing what works for you is important.