If you need to generate or refine your own "logo.png" file, several platforms offer specialized tools: How to insert a custom .png logo in header (Future2021)

PNG (Portable Network Graphics) is the industry standard for logos because:

Unlike JPEGs, PNGs support transparent backgrounds, allowing the logo to sit cleanly over any colored background or image without a white box around it.

They are universally supported across all browsers and social media platforms. 2. Where "logo.png" is Commonly Used

PNGs maintain sharp edges and vibrant colors even when compressed, which is essential for text and icons.

Often placed in folders like /images/logo/ or /assets/ so a website’s code can automatically pull it into the header.