Public sector, Private sector and Voluntary sector are the various heads under which the organizations can be classified. The three different sectors have distinct way of functioning, distinct objectives and a very different culture. A hybrid organization is the one that is a mix of all the above three.
An example of the same can be a public organization, whose management is changed to a private player. Hence, though the culture would be like a public organization the goals and objectives would be like a private firm.
Hybrid organizations face a major problem of the conflicts that happen due to clashes between different mind-sets.