They are distinct and not same.
A “thing” is a real entity which exists.
A “word” is a name represents an entity.
An “idea” is generated in the mind (memory) about a thing and its association to a word.
An example:
A COW as a thing is a cow. It is a specific entity which exists.
The word “cow” is a general name representing the thing cow for the people who speak English. The same thing is represented by multiple words, some call it a “gau”, some others “aavu” etc., even in the same language there are multiple words representing the same thing….
The idea “cow” is the impression of the thing cow and its association with the word cow in the mind. One remembers a cow when the word “cow” is heard or read.
The Confusion:
Generally people disagree due to the difference in ideas. There is absolutely no possibility of difference or confusion within the essential nature of the “thing” itself.
People can’t discriminate between these three and get into arguments. The agreement or disagreement is between two ideas and only between the ideas. The “thing-in-itself” is never impacted by ideas.
The Application:
Now apply this to the magic word “AHAM” or “I”
AHAM – “I” as a thing need to be understood completely. It is not the “I” as an idea in the Mind. The thing “AHAM” is absolute reality whereas the word “I” and the idea of “ego” are relative to the actual thing “AHAM” – “the self”.
This confusion between the THING and IDEA is called “AVIDYA” – Ignorance; The root cause of {all misery in} the world.
Realizing the AHAM – “self” as a thing devoid of words and ideas is knowing one’s own self; It is the highest goal of human form of life with its capability of discrimination.
Things can’t be completely explained by the words or ideas. One should perceive the thing to realize it.
AHAM BRAHMASMI – I am THAT absolute reality.
ॐ तत् सत्