When the stress moves, the meaning changes
How moving the stress from one syllable to the other turns a thing into an action in dozens of common word pairs.
We need to record the meeting so everyone has a record of the decisions.
A whole family of two-syllable words works as both noun and verb, and stress is what tells them apart: the noun stresses the first syllable, the verb stresses the second. The vowels change with the stress, because the unstressed syllable weakens, so the two versions genuinely sound different - not just louder in different places. When you meet a word of this type, learn it as two spoken words that happen to share one spelling.
Learners tend to pick one stress pattern per spelling and use it everywhere, usually the noun pattern. Stressing the wrong syllable does more damage than a wrong vowel - listeners often hear a different word, or nothing recognisable at all. When in doubt, apply the rough rule: first syllable for the thing, second syllable for the action.