On operads and infinity-operads

Abstract: 

Operads, invented in the early seventies by J.P. May, are a convenient tool for describing a variety of algebraic situations arising in homotopy theory, and have proven to be useful in many other areas in the intervening years. We will give a brief introduction to the concept, before moving on to a homotopy-coherent variant, based on the 'dendroidal objects' invented by Moerdijk & Weiss.