This is the 898th most frequent German word.
tatsache
Fact.
In this sentence, 'Tatsache' represents an undeniable fact which the subject comes to terms with.
Er akzeptierte schließlich die Tatsache, dass er einen Fehler gemacht hatte.
He finally accepted the fact that he had made a mistake.
'Tatsache' is used here to underline the importance of a specific truth or reality being communicated.
Die Wissenschaftler betonten immer wieder die Tatsache, dass ihre Ergebnisse überprüft werden müssen.
The scientists repeatedly emphasized the fact that their results must be reviewed.
Here, 'Tatsache' is used as a noun meaning 'fact', and serves to introduce an important piece of information that influences the speaker's feelings.