Atoms - basic HTML elements that can't broken down into smaller ones
Molecules - simple groups of atoms to form an element
Organisms - somewhat complex groups of atoms, molecules or other organisms
Templates - layout structure of a page
Pages - finished structure, content is detailed and correct inside of the template
Gutenberg Core Blocks have a wide range of Atomic Design elements from Atoms to Organisms.
Can reuse these blocks with little to no customization
Atomic Design can make the Gutenberg design process very granular from taking the most basic of elements (Atoms and Molecule blocks) and building them to Templates
Better control, text formats, styling and workflow by simply utilizing the tools provided by the plugin
Rich Text Formats that the Paragraph and Header blocks don't have included.
Estimated Reading Time shortcode
List Block formatting and styles
And many more Editor Design and Developer features
"A block template is defined as a list of block items. Such blocks can have predefined attributes, placeholder content, and be static or dynamic. Block templates allow to specify a default initial state for an editor session." From the Block Editor Handbook
Theme
Plugin
Editor itself
Block Templates are a collection of core or third party blocks to create a template
Gutenberg's Block Templates can be coded/created in three places:
Block Template in the Hestia theme (Theme Isle)
"Patterns are curated collections of blocks, often organized around a specific section or purpose. They make up common patterns across the web."
- Mel Choyce-Dwan
The Gutenberg 7.9 release sees three new blocks patterns added to the patterns core library
Although Block Patterns have been on the roadmap for almost 2 years, they are still relatively new within the Gutenberg and WordPress Cores.