  These are the notes for a minicourse held in Odessa (2016) and Belo Horizonte
(2017). My aim was to provide a short introduction to basic notions of category
theory and representation theory of finite-dimensional algebras. We learnt the
concept of adjoint functors and showed that the construction "quiver" <->
"algebra" can be interpreted as a pair of adjoint functors between certain
categories. Lectures almost do not contain the proofs, theoretical part is
accompanied with examples, and sometimes introduced in the form of exercises.
