Why do designers use a 12 column grid?

Question

css

As I understand it, the meaning of such a grid is that there are popular css frameworks that use such a grid (approx. bootstrap), in which the layout designer can set a certain number of columns for the blocks conceived by the designer. But, in fact, in most designs, the width of the blocks is not a multiple of the number of columns at all. Blocks protrude beyond gutters or capture only part of the column.
What's the point?

Answer 1

Read here

Answer 2

The point is that the creators of grid frameworks started from the old tabular layout. And a lot of bugs trail behind them, such a solution - wrappers, clearfixes... The block layout conceived in the HTML4 standard has little in common with the "vyser" that turned out in css frameworks.
And the article :@yarkov is very useful from the point of view of learning the basics of layout. Better yet, take some old book on the layout of newspapers, magazines. There, the basics of layout are described based on the basis.
PS Always surprises HTML, CSS which is written on frameworks. In addition to the framework, an additional style file is obtained, which is 2-3 times longer than the framework itself !! When you redo this mess, you get one style file half as short as just one framework.
PSS Artem Lebedev put it very wellon this occasion.

Answer 3

grid is just one way to organize a composition

Answer 4

The importance of the grid: artgorbunov.ru/bb/soviet/20110310
Choosing the number of columns: artgorbunov.ru/bb/soviet/20120307
Sergey Chikuyonok. Layout of stretchable sites
chikuyonok.ru/2010/01/liquid-site-markup

Answer 5

I'm not a designer, I'm a human orchestra. The concept of the site is born in my head and I make it up.
I use two grids - 12 and 10.
A 12-cell grid allows you to arrange elements in a row very conveniently. If we are talking about elements of the same width, then they can be 1, 2, 3, 4, 6, 12 in a row. At the same time, if you have, say, 4 elements in a row, it is very easy to make everything so that on a smaller screen you have 2 rows of 2 elements each. When using a grid, you maintain scale.
Why do I sometimes use a 10-cell grid? If I need to place 5 or 10 elements in a row. But this happens extremely rarely.
Pros:
1) Fast, easy, convenient.
2) A single dimensional grid is maintained, uniform sizes of indents.
3) There are many ready-made solutions.
Cons:
1) Dependence on the grid. For example, if you want to make a sidebar with a clear 300px, then you have to refuse the grid or adjust 100% of the grid width = 1000px, and allocate 3 units for the sidebar.