From The Free On Line Dictionary Of Computing:
<i>What is Dynamic Scoping and Lexical Scoping?</i>
In a progamming language with Nested Scopes, source code has a nested structure such that variable definitions can be introduced at any level of nesting.
<b>[This page should probably refactored with the pages Lexical Scoping, Dynamic Scoping, Lexical Closure and maybe Special Variable and Dynamic Extent.]</b>
W.A. Wulf, M. Shaw; <i>Global Variables Considered Harmful</i>, ACM SIGPLAN Notices 8:2, Feb 1973, pp. 80-86