About this tool
Useful when you need a file with no additional quality loss, or one that supports transparency in later edits. Keep in mind that going from JPG to PNG almost always makes the file bigger and the quality doesn't improve: it just stops getting worse.
If your photo is already a JPG, converting it to PNG doesn't recover lost detail; it lets you keep editing it without compressing it again.
JPG is the most common photo format; it's small but loses some detail. PNG is a lossless format that supports transparency.