what is flex display in css code example

Example 1: display flex

.container {
     display: flex;
     align-items: center;
     justify-content: center;
}

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Example 2: css all flex properties

.container {
  align-content: flex-start | flex-end | center | space-between | space-around | space-evenly | stretch | start | end | baseline | first baseline | last baseline + ... safe | unsafe;
}