A preamble is usually used for formal documents; you wouldn't include one in a text to your best friend. noun-A preliminary statement, especially the introduction to a formal document that serves to explain its purpose. noun-An introductory occurrence or fact; a preliminary.
Screw-in types can be used in place of incandescents in standard lamp sockets. Available in a wide spectrum of colors. Warm white tones best duplicate the color of incandescents. Today's fluorescent bulbs come in a wide selection of sizes and can produce warm tones of light similar to those of incandescents.
There are 3 types of bulbs that work well as grow lights: metal halide, high pressure sodium (HPS), and fluorescent. Each type of light fixture has its own advantages and drawbacks. 1  Metal halide bulbs are compact and efficient, producing a very intense light from a small bulb.