Gene expression is the process by which information from a gene is used to synthesize a functional gene product, typically a protein. This process involves two main stages: transcription, where the DNA sequence of a gene is copied into messenger RNA (mRNA), and translation, where the mRNA is used as a template to build proteins. The regulation of gene expression is crucial for cellular function and differentiation. In organisms, gene expression can be influenced by various factors, including environmental signals and cellular conditions. Understanding gene expression is essential for fields like genetics, biotechnology, and medicine, as it helps researchers uncover how genes contribute to health and disease.