What is The Difference Between PX, EM, REM, %, VW, and VH?

The units of measurement used to define sizes, particularly for font sizes, the most important aspect to learn about the different units is that some units such as "px," "em," "rem," "%," "vw," and "vh" are all units of measurement used in CSS to define sizes for various properties.

Why use PX, EM, REM, %, VW, and VH in css?

1. Pixels (px): Pixels are a fixed-size unit. When you specify a size in pixels, it will be rendered at that exact size on the screen. For example, width: 200px; sets the width of an element to be 200 pixels.
2. Ems (em): The "em" unit is relative to the font size of the element itself or its parent element. If you set an element's font size to 1em, it will be the same size as the font size of its parent. If you set it to 2em, it will be twice the size of the parent's font size, and so on. This unit allows for scalable designs where elements adjust their sizes relative to their parent or ancestor elements.
3. Root ems (rem): The "rem" unit is similar to the "em" unit, but it is relative to the font size of the root element (usually ). So, if you set an element's font size to 1rem, it will be the same size as the font size defined for the root element. This unit is particularly useful for creating scalable layouts that are independent of their parent or ancestor font sizes.
4. Percentage (%): The percentage unit is relative to the size of the parent element or the property being applied to. For example, width: 50%; sets the width of an element to be 50% of its parent's width. It can be used for width, height, padding, margin, and more.
5. Viewport width (vw): The "vw" unit is relative to the width of the viewport, which represents the visible area of the browser window. For example, width: 50vw; sets the width of an element to be 50% of the viewport width. It is useful for creating responsive designs that adapt to different screen sizes.
6. Viewport height (vh): The "vh" unit is similar to "vw," but it is relative to the height of the viewport. For example, height: 50vh; sets the height of an element to be 50% of the viewport height. It is also commonly used in responsive designs.

What is the difference between px and rem in css?

PX (Pixels): The "px" unit represents an absolute measurement of size. It refers to a specific number of pixels on the screen. For example, if you set a font size to 16px, it will be 16 pixels tall, regardless of the context or the user's preferences.

REM (Root EM): The "rem" unit is relative to the root element's font size. The root element is typically the element in HTML documents. If you specify a font size of 1rem, it will equal the font size of the root element. If you set the root element's font size to 16px, 1rem will be equivalent to 16 pixels. However, if you change the root element's font size, all elements that use "rem" units will adjust proportionally.

What is the difference between VH and VW in css?

VH (Viewport Height): VH is a CSS unit that represents a percentage of the viewport height. The viewport refers to the visible portion of the web page in the browser window. For example, if you set an element's height to 50vh, it will take up 50% of the height of the viewport.

VW (Viewport Width): VW is another CSS unit that represents a percentage of the viewport width. Similar to VH, it allows you to size elements based on a percentage of the viewport width. For instance, if you set an element's width to 25vw, it will occupy 25% of the width of the viewport.

Conclusion:

Pixels (px) are fixed-size units.
Ems (em) are relative to the font size of the element or its parent.
Root ems (rem) are relative to the font size of the root element (usually ).
Percentage (%) units are relative to the parent element or the property being applied to.
Viewport width (vw) units are relative to the width of the viewport.
Viewport height (vh) units are relative to the height of the viewport.