crop photo service help to make your image to all social media with any aspect ratio
now you may use alve photos to resize images at optimal quality and pixels exactly as determined
people who founders of websites that depended on images usually, which need to make their image low in size, so should compress it and get good quality because save bandwidth of his network and help speed load time for page, get more rank in search engine result.
photographer has photos with bad quality then need to optimize image at once.
designer has own some pictures going to change its dimension.
some of people wants to reduce image size. resize image for big dimensions.