Most fungi grow as hyphae, thread-like structures (2-10 µm in diameter and up to several centimeters in length). Hyphae grow at their tips (apices) and are typically formed by emergence of new tips along existing hyphae by a process called branching, or occasionally growing hyphal tips fork, giving rise to two parallel-growing hyphae. The combination of apical growth and branching/forking leads to the development of a mycelium, an interconnected network of hyphae. Hyphae can be either septate or coenocytic.