“The Natural Races” is a concept used by the dominant species of of "The Civilized Lands" to describe themselves. These include elves, half-elves, dwarves, gnomes, humans, and halflings. The term is used by these species to set themselves apart from the other “unnatural” species such as dragonborn, orcs, and goblins. These species are the products of magic (dragonborn) or curses and diseases (orcs and goblins). As such, many view them as abominations.
Gameplay:
In designing a player character, you will have to choose a race (species) and possibly a sub-race. “The Character Creation” section of The Player’s Handbook (p. 11) offers the base description of the each race and sub-race.
The races and sub-races of this world have their own peculiarities. Use the Player’s Handbook or Volo's Guide to Monsters for an overview of each race and sub-race and for a listing of stats and abilities. Use the following section to learn about the particular features, culture, geography, and religion of each race and sub-race that inhabitants this world, as well as any particular differences between them and the “standard” description of the race provided in the baseline game. The table on following page provides a brief overview.