:Stress:

The relative prominence of syllables. It is usual to distinguish lexical stress and sentence stress (also called rhythmic stress). The former may be thought of as a syllable’s potential to receive prominence and the latter the actual degree of prominence observed when a word is uttered as part of a longer utterance. The two often coincide, but not always. One common way of indicating stress is shown in ˌrestəˈreɪʃn where the two diacritic marks indicate secondary and primary stress respectively. Another method uses accents over the relevant vowel symbols: rèstorátion.