Custom and reusable blocks of content

Is there a way to create custom and reusable blocks?

The idea is simple. Create 20 custom blocks the client can use as needed.

– Header Image
– Service Carousel
– About us Headshot

So the client creates a new page, selects *Header Image and use the image they want, then selects *custom text and replace with their text, then an *About us headshot and replace with their content, etc…

The client will only select the pre made elements to use when they need.

How can this be done?

Thanks.