Vector files are built from mathematical paths. Raster files are built from pixels. That single difference affects how sharp your design stays when it scales, prints, or moves between tools.
Use vector for precision
Logos, icons, typography-heavy graphics, and simple illustrations should usually be vector because they can scale infinitely without losing clarity. That makes them ideal for print formats that change size often.
Use raster for texture and photos
Photographs, painterly artwork, and detailed textures belong in raster formats because they rely on pixel-level variation. The key is making sure the resolution is high enough at the final size.
Most real print workflows use both. The better you understand where each format belongs, the fewer quality problems you will see downstream.