The term town ball, or townball, describes the bat-and-ball, safe haven games played in North America in the 18th and 19th centuries, which were similar to rounders and were precursors to modern baseball. In some areas - such as Philadelphia and along the Ohio River and Mississippi River - the local game was called Town Ball. In other regions the local game was named "base", "round ball", "base ball", or just "ball." The players might be schoolboys in a pasture with improvised balls and bats, or young men in organized clubs. As baseball became dominant, town ball became a casual term to describe old fashioned or rural games similar to baseball.

The rules of town ball varied, but distinguishing characteristics most often cited were:

Generally the infield was a square or rectangular shape, with four bases or pegs. Similarly to baseball, the fourth base was called home base, as it was the final goal of a runner. However, differently from baseball - and more like rounders - the striker would stand between first and fourth base, at a kind of fifth base called the striker's stand. The thrower stood in the middle of the square and delivered the ball to be hit by the striker. If the struck ball were caught in mid-air or on the first bounce, the striker was called out. If no one caught it, the striker became a runner and advanced as many bases as possible, with the option to stop at any base as a safe haven.

A town is a human settlement larger than a village but smaller than a city. The size definition for what constitutes a "town" varies considerably in different parts of the world, so that, for example, many "small towns" in the United States would be regarded as villages in the United Kingdom, while many British "small towns" would qualify as cities in the United States.

The word town shares an origin with the German word Zaun, the Dutch word tuin, and the Old Norse tun. The German word Zaun comes closest to the original meaning of the word: a fence of any material.

In English and Dutch, the meaning of the word took on the sense of the space which these fences enclosed. In English, it was a small city that could not afford or was not allowed to build walls or other larger fortifications, and built a palisade or stockade instead (many early English settlements in North America used stockades.) In the Netherlands, this space was a garden, more specifically those of the wealthy, which had a high fence or a wall around them (like the garden of palace 't Loo in Apeldoorn, which was the example for the privy garden of William and Mary at Hampton Court). In Old Norse tun means a (grassy) place between farmhouses, and is still used in a similar meaning in modern Norwegian.

A ball is a round, usually spherical but sometimes ovoid, object with various uses. It is used in ball games, where the play of the game follows the state of the ball as it is hit, kicked or thrown by players. Balls can also be used for simpler activities, such as catch, marbles and juggling. Balls made from hard-wearing materials are used in engineering applications to provide very low friction bearings, known as ball bearings. Black powder weapons use stone and metal balls as projectiles.

Although many types of balls are today made from rubber, this form was unknown outside the Americas until after the voyages of Columbus. The Spanish were the first Europeans to see bouncing rubber balls (albeit solid and not inflated) which were employed most notably in the Mesoamerican ballgame. Balls used in various sports in other parts of the world prior to Columbus were made from other materials such as animal bladders or skins, stuffed with various materials.

As balls are one of the most familiar spherical objects to humans, the word "ball" is used to refer to, or to describe, anything spherical or near-spherical.