Check out example codes for "css grid area". It will help you in understanding the concepts better.

Code Example 1

.item1 {
  grid-area: 1 / 1 / 5 / 5; /*Start on row 1, column 1. End on row 5, column 5*/
}

.item2 {
  grid-area: 5 / 5 / span 2 / span 2; /*Start on row 5, column 5. End on row 7, column 7*/
}

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