You can think of a hash as being like an array, only using a unique string as a key rather than a unique number as an index. (push adds an element at the end of an array, so you never need to know the index. With a hash, you have to explicitly specify what the key is, as in for example, "Sample 17".)

Take a minute and read the Data Type: Hash tutorials. Again, if you have explicit questions, don't hesitate to ask.