Vector vs Bitmap ? its two different data formats. Bitmap used as a lifetime picture and Vector is commonly used for something abstract like logos. From my observation, bitmap is using a pixel taken from a digital camera or scanner, but vector is not used pixel it use mathematical description. Mathematical description is based on how it drawed by a person and change it into a picture. Other than that, bitmap usually save in a huge depends on size file but vector created in a small file no matter how size it is.
Resources : 1) https://www.prepressure.com/library/file-formats/bitmap-versus-vector