Whether you’re designing graphics for a banner stand, a fabric exhibit or a rigid hanging sign, large format trade show graphics are a unique breed. Typical rules and guidelines for designing standard graphics do not necessarily apply when preparing files for large format printing.
Photoshop is strictly raster-based and mainly used for photo/image editing. Because the images are composed of pixels, raster graphics scale down with no loss of quality but enlarging will cause pixilation.
When using Photoshop, be sure your images are high resolution enough to fit the large print space. If you are creating design elements like shapes or blocks of color, Illustrator is best.