The lynch is the Town's collective killing method. The majority of living players (both Town and scum) generally must agree on who to lynch by casting votes for the person they want to see dead.
This is frequently the Town's only means of killing anyone, and in most cases it is the most reliable way of doing so as well. In particular, the only active ability a Vanilla Townie has is the ability to help direct who gets lynched on a given Day.
Once a player receives a majority vote, that player is typically killed at the earliest opportunity the moderator gets. Upon death, the moderator will reveal the deceased player's role and alignment (unless the game mechanics say otherwise). Afterward, the game will proceed to Night.
On a linguistic note, "lynch" is a term that refers to an extrajudicial killing, and fits with the traditional theme of the players forming an angry mob. While no racial connotation is intended with the term, one should still be careful when saying it in MeatWorld.