The process whose specific outcome is the progression of lymph nodes over time, from their formation to the mature structure. A lymph node is a round, oval, or bean shaped structure localized in clusters along the lymphatic vessels, with a distinct internal structure including specialized vasculature and B- and T-zones for the activation of lymphocytes. [ http://openisbn.com/search.php?q=0781735149&isbn=1/ http://openisbn.com/search.php?q=068340007X&isbn=1/ GOC:add ]