how does grid template work css code example

Example 1: how to use a blank space with grid template areas css

.container {
  display: grid;

  grid-template-columns: 2fr 2fr 1fr 2fr;
  grid-template-rows: 100px 200px 100px;

  grid-template-areas:
    "head head . side"
    "main main . side"
    "footer footer footer footer";
}

Example 2: grid template areas

/* Keyword value */
grid-template-areas: none;

/* <string> values */
grid-template-areas: "a b";
grid-template-areas: "a b b"
                     "a c d";

/* Global values */
grid-template-areas: inherit;
grid-template-areas: initial;
grid-template-areas: unset;