Text register

Upper, lower case

You can change the case of the text (make the letters small or large) through the text-transform property.

p {
    /* lower case (Html => html) */
    text-transform: lowercase;

    /* Upper case (Html => HTML) */
    text-transform: uppercase;
}

Capitalize first letter

There is no property in CSS that makes the first letter capitalized. But you can select the first character of the text through the pseudo-element :first-letter, and apply the text-transform: uppercase property to it.

/* html code => Html code */
p::first-letter {
  text-transform: uppercase;
}

Capitalize each word

Capitalize each word using the text-transform: capitalize property.

p {
    /* html code => Html Code */
    text-transform: capitalize;
}