Chromatin has several functions, the main one being to condense the six feet of DNA in every cell down to fit inside the nucleus. The chromatin is also responsible for helping transcribe RNA, help prevent the DNA from being damaged while being compacted inside the nucleus, and assist in gene expression.
There are two basic types of chromatin, the euchromatin and the heterochromatin. The euchromatin is involved in the transcription of RNA, which helps produce proteins for the production of energy. These chromatins are more diffused than other types. The heterochromatin holds the genes that are silent, or not expressed during the gene expression. The DNA held in the heterochromatin is referred to as being genetically inactive.