What is major ritual impurity (janabah), and is the emission of semen (manyi) and pre-seminal fluid (madhyi) with desire forbidden for the unmarried?

Janabah is an impurity that necessitates ghusl (ritual bathing). It is caused by the emission of semen with desire, or by the meeting of the two circumcised parts. It is called janabah because it is a reason to avoid prayer. The emission of semen or pre-seminal fluid has two scenarios: either due to intercourse or foreplay, and there is no sin in this, or due to transgression against the limits of Allah, such as masturbation or forbidden looking, and this is impermissible.