This is the 11778th most frequent Russian word.
заключает
"Concludes" or "encompasses."
In this sentence, 'заключает' means 'concludes' or 'ends' and is used to indicate how someone finishes something, in this case, an article.
Автор заключает статью словами благодарности.
The author concludes the article with words of gratitude.
Here, 'заключает' is used in the context of formal agreements, meaning 'makes' or 'concludes' a deal or contract.
Он заключает сделку с партнёром.
He is making a deal with a partner.
In this usage, 'заключает' is used to indicate drawing a conclusion or summarizing findings.