What does the display property control?

Question

Accepted Answer

`display` is one of the most fundamental CSS properties — it controls **how an element generates a box** and how its children are laid out.

```css
.a { display: block; }        /* full width, starts new line (div, p, section) */
.b { display: inline; }       /* flows in text, ignores width/height (span, a) */
.c { display: inline-block; } /* flows inline BUT respects width/height/margins */
.d { display: none; }         /* removed entirely — no space, not rendered */
.e { display: flex; }         /* flex container — 1D layout for children */
.f { display: grid; }         /* grid container — 2D layout for children */
```

## Outer vs inner display

`display` actually sets two things: how the box behaves **outside** (block/inline) and how it lays out its **children** inside (flow/flex/grid). `display: flex` means "this box is block-level, and its children are flex items."

## display: none vs visibility: hidden

```css
.gone   { display: none; }        /* removed from layout — takes NO space */
.hidden { visibility: hidden; }    /* invisible but STILL occupies its space */
```

A key distinction: `display: none` collapses the layout (and hides from screen readers); `visibility: hidden` leaves a gap where the element was. Use `display: none` to truly remove, `visibility: hidden` to hide while preserving layout.

## The layout workhorses

```css
.container {
  display: flex;          /* lay children in a row/column (one dimension) */
  gap: 1rem;
}
.grid {
  display: grid;          /* lay children in rows AND columns (two dimensions) */
  grid-template-columns: repeat(3, 1fr);
}
```

Modern layout is built almost entirely on `flex` (1D — rows or columns) and `grid` (2D — rows and columns together).

## Why it matters

`display` determines an element's entire layout behavior.

Knowing block vs inline vs inline-block explains default flow; `flex`/`grid` are the core of modern layout; and the `none` vs `visibility` distinction is a frequently-tested, practically-important detail.