Chromatin is a complex of DNA and proteins found in the nucleus of eukaryotic cells. It plays a crucial role in packaging DNA into a compact, organized structure, allowing it to fit within the cell nucleus. Chromatin exists in two forms: euchromatin, which is loosely packed and accessible for gene expression, and heterochromatin, which is tightly packed and generally inactive. The primary proteins in chromatin are called histones, which help to coil and condense the DNA. This organization is essential for processes such as DNA replication and gene regulation, ensuring that genetic information is properly managed and expressed when needed.