The first thing to understand when considering a Disney Theme Park vacation is which park is which. Disney owns parks in five cities around the world including Hong Kong, Paris, Tokyo, Orlando and Anaheim. In the US, if you are considering a Disney Theme Park you could be referring to either the East or West Coast.
The first Disney Park opened in the year 1955 in Anaheim, California. This location was simply called Disneyland after the animator and producer Walt Disney. The park is divided into several major sections including Tommorowland, Frontierland, Adventureland, Mickey’s Toontown, and Main Street, USA.
But, as they say, Walt's dreams were larger than life and they needed room to expand. Limited in space availability in California, Disney set out to purchase inexpensive land in Orlando, Florida. Walt Disney, however, would not live long enough to see his dreams unfold. Walt Disney World opened in 1971, just under 5 years after Walt’s death. Many rides were actually recreations of some of Walt's conceptual drawings and several rides would be replicated from Disneyland into the new park. Walt Disney World would also expand well beyond the scale of Disneyland. Later additions included Disney Hollywood Studios (formerly MGM Studios), Animal Kingdom, EPCOT and two water parks. The heart of the parks would be called The Magic Kingdom and would feature replicas of many of the rides and attractions in Disneyland.
Many Surrounding restaurants and attractions are also similar between the two parks. Both feature a Disney owned feature called Downtown Disney; both have Rain Forest Cafes; and both have extensive hotel chains associated directly under the ownership of the park.
To sum it up: Disneyland (when referring to a park in the USA) is in Anaheim, California and Walt Disney World is located in Orlando, Florida.