The ::-moz-range-progressCSSpseudo-element represents the portion of the "track" (the groove in which the indicator aka thumb slides) of an <input> of type="range", which corresponds to values lower than the value currently selected by the thumb.
The ::-moz-range-thumb CSS pseudo-element represents the thumb, the virtual knob the user can move within the groove, or track, of an <input> of type="range" to alter its numerical value.
The CSS ::afterpseudo-element matches a virtual last child of the selected element. It is typically used to add cosmetic content to an element by using the content CSS property. This element is inline by default.
The ::-ms-fill CSS pseudo-element represents the filled-in portion of a <progress> element. This pseudo-element is non-standard and specific to Internet Explorer 10+, hence the vendor prefix.
The ::selection CSS pseudo-element applies rules to the portion of a document that has been highlighted (e.g. selected with the mouse or another pointing device) by the user.
Each element in the top layer's stack has a ::backdroppseudo-element. This pseudo-element is a box rendered immediately below the element (and above the element below the element in the stack, if any), within the same top layer.
The ::-ms-fill-lowerCSSpseudo-element represents the portion of the "track" (the groove in which the indicator aka thumb slides) of an <input> of type="range", which corresponds to values lower than the value currently selected by the thumb.
The ::-ms-fill-upperCSSpseudo-element represents the portion of the "track" (the groove in which the indicator aka thumb slides) of an <input> of type="range", which corresponds to values greater than the value currently selected by the thumb.
The ::-ms-thumb CSS pseudo-element represents the "thumb" that the user can move within the "groove" of an <input> of type="range" to alter its numerical value.
The ::placeholder CSS pseudo-element represents the placeholder text of a form element. This allows web developers and theme designers to customize the appearance of placeholder text.
The non-standard proprietary ::-webkit-input-placeholderpseudo-element represents the placeholder text of a form element. This allows web developers and theme designers to customize the appearance of placeholder text. This pseudo-class is only supported by WebKit and Blink.
The ::-webkit-slider-thumb CSS pseudo-element represents the "thumb" that the user can move within the "groove" of an <input> of type="range" to alter its numerical value.