Project Object Model: It is the fundamental unit for Maven Related Projects.Its basically a xml file which contains the project structure,dependencies,configuration details required to build the project.

For more info: Introduction to the POM

Page Object Model: Its a design pattern required to create Object Repository for UI Elements. As per this model,for each Page there has to be a Page class.This page class will have Web Elements of the Web Page along with the methods that perform operations on these web elements.