Here are the kinds of information dictionaries may give about a word:
Spelling
Syllable divisions or syllabification, usually indicated by a dot: let·ter
Pronunciation, including common alternate pronunciations. Online dictionaries often provide audio links that allow you to hear the pronunciation.
Parts of speech. Many words can be used as more than one part of speech; for instance, sign can be either a noun or a verb.
Other forms of the word
Idiomatic uses and phrasal verbs
Usage notes
The languages the word comes from, known as etymology
Field labels that indicate how a word is used in a particular discipline or profession
Synonyms (words with the same or similar meanings)