  This is the first part of my lectures on the Pomeron structure which I am
going to read during this academic year at the Tel Aviv university. The main
goal of these lectures is to remind young theorists as well as young
experimentalists of what are the Reggeons that have re-appeared in the high
energy phenomenology to describe the HERA and the Tevatron data. Here, I show
how and why the Reggeons appeared in the theory, what theoretical problems they
have solved and what they have failed to solve. I describe in details what we
know about Reggeons and what we do not. The major part of these lectures is
devoted to the Pomeron structure, to the answer to the questions: what is the
so called Pomeron; why it is so different from other Reggeons and why we have
to introduce it. In short, I hope that this lectures will be the shortest way
to learn everything about Reggeons from the beginning to the current
understanding. I concentrate on the problem of Reggeons in this lectures while
the Reggeon interactions or the shadowing corrections I plan to discuss in the
second part of my lectures. I include here only a short lecture with an outline
of the main properties of the shadowing corrections to discuss a correct (from
the point of the Reggeon approach) strategy of the experimental investigation
of the Pomeron structure.
