Question: Here is one sentence: This is the one I ordered.
Here is another sentence: He is the best one.
Does the one mean the same thing in the two sentences?

Answer: the same meaning

Question: Here is one sentence: His conclusion took the evidence into account.
Here is another sentence: In conclusion I want to say ...
Does the conclusion mean the same thing in the two sentences?

Answer: different meanings

Question: Here is one sentence: We'll get them!
Here is another sentence: She didn't get the joke.
Does the get mean the same thing in the two sentences?

Answer: different meanings

Question: Here is one sentence: The line stretched clear around the corner.
Here is another sentence: A dedicated line.
Does the line mean the same thing in the two sentences?

Answer:
different meanings