In design, a grid refers to a system of horizontal and vertical lines or guides that are used to structure and organise content on a page or screen. A grid provides a framework for designers to align elements such as text and images in a way that creates balance, hierarchy and visual harmony. Grids can be used in various types of design to create layouts that are aesthetically pleasing and easy to navigate. It can be based on different principles such as the rule of thirds, golden ratio, or modular design, and can be customised to fit the specific needs of a project.