For load images from server you can use SDWEBIMAGE . Download this github link and Copy this into your project. Now You need to,
#import <SDWebImage/UIImageView+WebCache.h>
Then you can Do this,
[YourImageView setImageWithURL:[NSURL URLWithString:@"Your URL link"]
placeholderImage:[UIImage imageNamed:@"placeholder.png"]];
Where Placeholderimage is default image when image is not available on server. Hope this help you!