The settings in Settings -> Media will affect the ability to upload media files (images / videos / music, ..) to your content.
- Image sizes: These settings determine the default WordPress image size generated after uploading an image to library.
- Thumbnail size: Image size of thumbnail.
- Crop thumbnail to exact dimensions… .: Create a thumbnail image by cropping the original image with the exact same size as the setting.
- Medium size: Image size medium.
- Large size: Large image sizes
- Uploading Files: Settings related to file upload.
- Organize my uploads into month- and year-based folder: Automatically upload uploaded files into folders with date structure compared to upload time.