The total complement of genetic information contained in a particular organism's chromosomes. This includes coding genes, but also non-coding regions.
It is sometimes taken to mean the information stored in just a single (haploid) set of nuclear chromosomes, but depending on the context, the term genome may include mitochondrial DNA and both sex chromosomes. Therefore, the sequenced human genome includes the entire nucleotide sequences of all the chromosomes.
The field of study of the genome is called genomics. The genome contains an estimated 20000 to 25000 genes. However, due to changes after transcription and post-translational modification, the number of possible proteins is considerably more and is estimated at 400000.
This complexity has given rise to a further field called proteomics. This is study of structure and function of the immense number of peptides and proteins, many of them produced in different organs, tissues and cells at different times in a organisms life.