Caption hover effect on images

Hi

I’m very sorry if this has already been discussed and solved but I’m stuck and don’t know what to look for.

I want to create a gallery with square thumbnails/images. Click the thumbnail/images and you’ll be taken to a dedicated page. I want a hover effect on the images, with a transparent background, a heading and text saying something about the content on the linked-to page. I see that many pro/paid themes has feature images with this effect.

Is there any way to achieve what I’m looking for? Thanks for your time.