A copy of the rendered word is placed behind it at the offset and angle, grown by Spread and softened by Feather. The feather is built as nested vector bands with solved opacities, so it prints as vector rather than a raster blur.
Shadow is applied as an Illustrator live effect, so the text stays editable. Change the word, the font, or any slider afterwards, and save the result as a Graphic Style to reuse it.
How to add a shadow to text in Illustrator → walks through the manual Illustrator steps, then shows the one-click version.