PNG

PNG (Portable Network Graphics) is a lossless image format, meaning it compresses without throwing any detail away. What goes in comes back out pixel-for-pixel, which makes it ideal for screenshots, logos, icons, charts, and anything with sharp edges or flat areas of color.

PNG's standout feature is transparency: it supports a real alpha channel, so an image can have see-through areas and soft edges that blend over whatever is behind it. That is why logos and UI graphics are almost always PNG. The downside is size, because lossless compression cannot shrink a complex photograph nearly as much as JPG can.

The rule of thumb when building or exporting PDFs: use PNG for graphics with crisp lines, text, or transparency, and reach for JPG when you are dealing with full photographs where smaller size matters more than perfect fidelity.