As discussed here, chromosomes are composed of 4 different chemical letters: A, T, C, G.  The goal of the Human Genome Project was to determine the sequence of these letters for every single chromosome.  This   was a huge undertaking, given that there are about 3 billion chemical letters contained within our genome. 

In 2001, the first draft of this human genome sequence was completed. Based on the results of this project, we know that humans have between 20,000 and 30,000 genes.  However, even though we know the sequence of the human genome, many questions remain to be answered.  We still do not understand the function of many of these genes.  In addition, we do not completely understand how changes in these genes can affect an individual.

In summary, the Human Genome Project does not provide us with all the answers. However, it does provide us with the tools we need to start answering our questions.