Ye with acute
|The Cyrillic script|
Ye with acute (Е́ е́; italics: Е́ е́) is a letter of the Cyrillic script. In all its forms it looks exactly like the Latin letter E with acute (É é É é).
Being a relatively recent letter, not present in any legacy 8-bit Cyrillic encoding, the letter Е́ is not represented directly by a precomposed character in Unicode either; it has to be composed as Е+◌́ (U+0301).
|Unicode name||CYRILLIC CAPITAL LETTER IE||CYRILLIC SMALL LETTER IE||COMBINING ACUTE ACCENT|
|UTF-8||208 149||D0 95||208 181||D0 B5||204 129||CC 81|
|Numeric character reference||Е
|Named character reference||Е||е|
⟨Е́⟩, just like any other stressed (accented) Cyrillic vowels are mostly found in East Slavic languages in words like уже́ or в душе́.Words that have letters like ⟨Е́⟩ are used mainly if the word is longer than one syllable and are fundamental to use in the East Slavic languages.
Words need to use an accent if a word is longer than one syllable. These letters that are stressed (accented) are fundamental 
Letters like these are important and are needed so that native speakers are able understand the word's meaning and pronounciatiion and is necessary to put letters like these in languages like this in words to give the word a more meaningful sentence or phrase in texts.