A "point" (abbreviated as "pt") is a unit of measurement commonly used in typography and desktop publishing to specify the size of text, fonts, and other elements on a printed or digital page. The point is part of a system of measurement used in the field of typesetting, which involves arranging and designing text for printed materials.
In the point system:
1 point (abbreviated as "pt") is equal to approximately 1/72nd of an inch. This means that there are approximately 72 points in 1 inch.
Points are used to define the size of fonts, leading (line spacing), and other layout details in printed materials. For example, when you specify a font size of 12 points, you are indicating that the height of the characters in that font will be roughly 1/6th of an inch or about 4.23 millimeters.
Points are still widely used in the design and printing industry, especially when specifying font sizes, line spacing, and other layout details for printed materials like books, magazines, and newspapers. In digital design and modern desktop publishing software, you can often switch between using points and other units like picas, inches, millimeters, or pixels to set and adjust the layout of text and graphic elements.
A perch is a unit of length that was historically used in some English-speaking countries, primarily in the United Kingdom. It is equivalent to 5.5 yards or 16.5 feet (about 5.0292 meters). The term "perch" is relatively old and is not commonly used in modern measurements.
Perches were often used in land measurement, particularly in agriculture and real estate. They were also sometimes used in surveying. However, the use of the perch as a standard unit of measurement has largely been replaced by more modern and standardized systems such as the metric system or the imperial system based on feet and yards. As a result, the perch is considered an archaic or historical unit of measurement today.