Before taking up the discussion of the functions and operations of the bank, it may be well to make a classification of the various types of banking institutions with which the modern world is familiar. Banking institutions may be roughly classified as follows:

I. Private banks.

II. Public or chartered banks.

1. Savings banks.

2. Trust companies.

3. Commercial banks.

(a) State banks.

(b) National banks.

To these might be added mortgage banks, exchange banks, loan and investment companies, and other special kinds of banking institutions, but the groups above embrace the most important types in the United Stales.