Image Sizing Using Customzr Theme

For the homepage slider, the default image size is 1170 x 500 (or whatever height you select), so edit your image to that size. The featured image thumbnails are 270 x 250, just like it says.

Agree with @wills173. See the doc. You should use the Regenerate Thumbnails plugin to reset all your Images.

Let me ask, does all this mean that WP will only allow one size image in all posts and pages? Does it mean that all uploaded images must be uploaded the exact size I want it to be.

I enter my image sizes in the option, update it, and when I go back to the post edit, the image is resized properly. However, when I look at the site post, the image is as large as it is. Can I not resize my images per html width=”x” height=”X” in the image tag?

This makes no sense to me because all images are not the same size and all posts may not require the same size images. Many images will be various sizes. How on earth am I supposed to size my images on the fly without resizing them to exact before uploading? Any suggestions? Thanks