Who was Johannes Gutenberg and what was the significance of his invention?

Johannes Gutenberg was a German blacksmith known for inventing the mechanical movable type printing press. His printing press has been widely considered the most important invention of the modern era because it profoundly impacted the transmission of knowledge.

Explanation:

johannes Gutenberg was a German blacksmith known for inventing the mechanical movable type printing press. His printing press has been widely considered the most important invention of the modern era because it profoundly impacted the transmission of knowledge.

Explanation:

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering

the answers are a b and d