What is smurfing in League of Legends?

Have you ever came across a highly skilled player on a low rank? Smurfing in League of Legends is a big issue, but why do players do it?

What does Smurf mean? A League of Legends Smurf Guide

smurfing Archives - Esports News UK

Cheap LoL Smurfs aren't everything they claim to be

Smurfing' And 'Smurfs' In Video Games: Everything You Need To Know

Are League Smurf Allowed?

Why can people just smurf, acknowledge they are smurfing and not get banned. : r/leagueoflegends

League Of Legends - All you need to know about smurfing

How to spot a smurf account in League of Legends

League dev explains how Riot is solving Clash's smurfing problem - Dexerto

Meaning of smurf in League of legends LoL