In this paper we observe the notion of an operad, more precisely a topological operad, and some of its applications. The term operad, as it is known today, was first introduced in the work of Peter May, [7], for the purposes of characterizing iterated loop spaces, though, towards the end of the twentieth century, it finds its applications in other branches of mathematics. This paper is organized into three chapters, with an appendix that contains basic results of category theory and topology required for its understanding. In the first chapter we define operads and \(\mathcal{P}-\)spaces along with monads and algebras over a monad. We go over some basic examples of such objects and describe two basic constructions, one that associates to an operad \(\mathcal{P}\) its corresponding monad \(P\), such that algebras over the monad \(P\) characterize \(\mathcal{P}\)-spaces, and another that gives a certain resolution \(W (\mathcal{P})\) of the monad \(P\). The second chapter deals with the little cube operad, the key object in May’s work on the loopspace recognition principle. We describe the natural action of the little cube operad on iterated loop spaces and briefly go over May’s two main resutls. In the last section of the chapter we show that the little cube operad is homotopy equivalent to configuration spaces \(F(\mathbb{R}^n, \cdot)\). We also describe a compactification of those configuration spaces and its associated operad structure, the Kontsevich operad. The third chapter follows the work of Ryan Budney, [3], which describes the weak homotopy type of the spaces of long knots \(\mathcal{K}\). Budney’s work is loosely based on the work of Schubert, [11], in which it is shown that the connected sum operation induces a commutative monoid structure on \(\pi_0\mathcal{K}\). We define the little 2-cube action on a certain model for \(\mathcal{K}\) and follow Budeny’s proof mainly focusing on the mentioned action.