We got many tickets to this image links issue. It's very common for HTML learners and who are newly trying to create a HTML website. So beware about the file path and file extension. Locally it will display both lower and uppercase extension images ( .jpg and .JPG ) but Server does not.
1) Check your HTML path and uploaded directory path is same.
Ex: img/sample.jpg should uploaded in img folder on server
2) Check your image code in HTML whether added same file extension or not
Ex: If you uploaded sample.jpg on server you should specified image name with extension like sample.jpg and don't do sample.JPG.