A concrete noun is a word for something that can be experienced by any of the five physical senses; something that can be seen, heard, smelled, tasted, or touched.
An abstract noun is a word for something that can't be experienced by any of the five physical senses; something that is known, learned, thought, understood, or felt emotionally.
Examples of concrete nouns / abstract nouns:
a verb that causes the subject to perform the action.
Captain carpenter humbly accepted the purple heart.
Vivid nouns produce distinct mental imagery for readers.
A diary
i want to use adverbs in my work.
Concrete nouns and active verbs create a more powerful effect in quality writing.
Ernest Henry Shackleton was known as a brave explorer who was also cautious and wise when he traveled.
Rephrasing a thesis.