Explain Criteria API

Criteria is a simplified API for retrieving entities by composing Criterion objects. This is a very convenient approach for functionality like "search" screens where there is a variable number of conditions to be placed upon the result set.
Example :

List employees = session.createCriteria(Employee.class)
           .add(Restrictions.like("name", "a%") )
           .add(Restrictions.like("address", "Boston"))
    .addOrder(Order.asc("name") )
    .list();