A conlang is a language created by a person or people, in contrast to a natlang which is a language that evolved in the usual way over centuries and has native speakers. Conlanging is the act of language creation, and for me is a kind of devotional and religious or meditative practice.
Some examples of Conlang I like include Quenya, Sindarin and all those Tollkien ones, Klingon, Toki Pona, etc.
I’ve added a page for a conlang I’ve created called yupiche, generated with a tool called VulgarLang.