Collections are a tremendous help when dealing with large amounts of similar data. Without them, you would have to literally create a new variable for each piece of data, which of course would be nearly impossible. The .NET Framework contains many predefined collections you can use. This hour covered the collections used most frequently, but as you dig deeper into the .NET documentation, you will find many more specialized collection classes.
Due to the nice design of the .NET Framework collection classes, you'll find that working with these different collections is quite similar, which frees you from having to learn new methods all the time.
The key to selecting a certain collection class is knowing the advantages and disadvantages of each one. Although an array might not be a good choice for one application, it might later prove to be the best collection choice for a different application. In other words, there is no collection class that is better than the other. It all depends on the requirements of the application you are creating.