A list is a series of items belonging to a specific category, such as colors, vehicles, and countries.
Depending on the order in which the items of a list are arranged in a sequential or logical order; that is why, this list is also called a sequential list. On the other hand, there is no specific sequence or order to place items in an unordered list.
In HTML, ordered lists are marked with numbers or letters; whereas, unordered lists are marked with different types of images or bullets.
All these symbols, numbers, and letters with which the items of a list are marked are known as list item markers.
HTML also provides Cascading Style Sheet (CSS) that allows you to set various list-style properties to define the style of the list item markers for both ordered and unordered lists.
These list style properties are: