How does growth differ from cell multiplication during development?

In the context of biological development, "growth" is a broad term encompassing the overall increase in the size of an organism or its parts, while cell multiplication (cell division) is one of the specific mechanisms that drive this process.1

The distinction between these two concepts can be summarized as follows:

• Definitions: Growth refers to the general phenomenon of increasing size, which is achieved through two primary aspects: an increase in the number of cells (via cell division) and an increase in the size of individual cells (hypertrophy).1
• Independence: These processes can occur independently. For example, some tissues grow primarily by increasing cell numbers while maintaining a constant cell size, whereas other organs, such as insect salivary glands, grow through the enlargement of existing cells without increasing their number.1
• Developmental Patterns: During early embryonic development, cells may undergo repeated divisions without intervening growth periods, resulting in many small cells. Conversely, in later stages or specific tissues, growth often involves a combination of both division and cellular enlargement.21
• Regulation: While cell division is a precise reproductive mechanism (mitosis), growth is a quantitative increase that can be influenced by environmental factors, nutrient availability, and genetic constraints.23