  SYK model and 2D dilaton gravity have recently attracted considerable
attention from the high energy and condensed matter physics community. The
success of these models is due to their remarkable properties. Following the
original papers, we broadly discuss the properties of these models, including
large $N$ diagrammatics, emergence of conformal symmetry in the IR limit,
effective action, four-point functions and chaos. Also we briefly review some
recent results in the topic. On the one hand, we try to be as specific as
possible, i.e. reveal every detail and loophole in the discussion. On the other
hand, we expect this review to be suitable even for a reader who is not
familiar with these models.
