The gel-like substance found inside cells is called cytoplasm. This semi-fluid medium surrounds the organelles and is primarily composed of water, salts, and organic molecules, facilitating various cellular processes. The cytoplasm provides a site for metabolic reactions such as protein synthesis and energy production. Additionally, it helps transport materials within the cell and contributes to maintaining cell shape and structure. Understanding cytoplasm is essential in cell biology, as it plays a critical role in the functionality and overall health of cells.