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 TGA?

Targa dates to 1984 and refuses to die, because game engines and 3D packages standardised on it for textures and never had a reason to move. It keeps an alpha channel, optionally compresses runs of identical pixels, and is simple enough that every tool reads it.