The next seven days provide you with a solid foundation in object-oriented programming. Day 1 describes the basics of OO. You learn about object oriented from a historical perspective and see how OO evolved from existing programming languages. You also learn basic terminology as well as benefits and pitfalls of object-oriented programming.
Days 2, 4, and 6 introduce you to the three pillars of object-oriented programming: encapsulation, inheritance, and polymorphism. These chapters not only explain the basics of object-oriented programming, but how and when to use them as well as mistakes to avoid.