Wood texture is a key characteristic to classify the wide variety of existing types of wood. As trees grow, they develop clear marks of their own identity. Depending on whether their growth is fast or slow, the section of their rings will change in width. Fast growing trees have wider rings, resulting in softer wood, while slow growing trees have more compact rings and yield harder wood. Below is a classification of woods, including their main characteristics. Resinous Woods Come from slow growing trees. They grow in cold or mild weather regions and are considered an ideal material due to their excellent mechanical resistance. This is the most common type of wood used in carpentry and construction projects. Most common examples are: pine, fir and larch. Non-Coniferous Woods Come from trees typically found in mild weather regions. These are leafy trees with many branches. There are three different groups: hardwood, softwood and fine wood. Hardwoods include oak and beech. Softwoods include birch and poplar. Fine woods include walnut, cherry, apple, olive and other fruit trees. Exotic Woods Are sought for their high resistance, which enables better finishes. This group includes mahogany, iroko /odum, ebony, teak, palisander, rosewood, etc. Composition Like all other organic materials, wood is made of cells held together by lignin. Its primary elements, which are the basis of its physical and mechanical properties, can be seen in the table below. CONIFEROUS Cellulose 50% Hemicellulose 23% Lignin 27% NON-CONIFEROUS Cellulose 50% Hemicellulose 26% Lignin 24% SECONDARY ELEMENTS (impregnations - not part of cell membrane) Carbon 50% Hydrogen 5,4% Nitrogen 0,1% Oxygen 44% Ashes 0,5%