What is SVG?

Not pixels but instructions - shapes, paths and text that a browser draws at whatever size you ask for. That makes it perfect for logos, icons and diagrams, and useless for photographs. Converting an SVG to any other format here is the moment it stops being able to scale.

What is PPM?

Uncompressed RGB behind a four-line text header - about as simple as an image format can be while still being one. Nobody ships PPM to users; it exists as the thing scripts and teaching code write when they'd rather not link an image library.