In graphic design, a grid is a structure (usually two-dimensional) made up of a series of intersecting straight (vertical, horizontal, and angular) or curved lines (grid lines) used to structure content.
By the mid-1970’s instruction of the typographic grid as a part of graphic design curricula had become standard in Europe, North America and much of Latin America. The graphic style of the grid was adopted as a look for corporate communication. In the early 1980’s, a reaction against the entrenchment of the grid, particularly its dogmatic use, and association with corporate culture, resulted in some designers rejecting its use in favor of more organic structure. The appearance of the Apple Macintosh computer, and the resulting transition away from type being set by typographers to designers setting type themselves resulted in a wave of experimentation, much of it contrary to the precepts of Tschichold and Müller-Brockmann. The typographic grid continues to be taught today, but more as a useful tool for some projects, not as a requirement or starting point for all page design.
https://en.wikipedia.org/wiki/Grid_(graphic_design)
While researching grids and how they are used in graphic design terms i came across this article which has so much information and images and even how to use grids effectively as a designer!
https://trydesignlab.com/blog/grids-ui-ux-graphic-design-quick-history-5-amazing-tips/#3
GC Graphic Design 