A dictionary is a powerful tool. It gives the description or meaning of a word; but there is a lot of other information that you can get from it.
The following elements can be found when we look for a word:
The meaning of the word: we can know what a word means thanks to a dictionary. There are usually more than one meaning for the same word. You should decide which description is the most suitable for a context.
The spelling of the word: how the word is written. This is very important in English, since there are double letters, silent letters, and letters that sound different each time...
The sound of the word: in a good dictionary, you will find a phonetic transcription using a particular alphabet (known as IPA). Online dictionaries usually provide an audio file where you can listen to the word in different accents! (British, American, Scottish...)
The type of word: we can check if the word is a noun, an adjective, a verb, an adverb, a preposition, or a conjunction. The same word can have different functions (noun and verb, for example), and this is also indicated in the dictionary. A small letter next to the word tells us the type of word it is (v=verb, n=noun, adj=adjective...)
The syllables that the word has: some dictionaries show the number of syllables a word has. This is marked by separations through points "·". For example: /to'mei·to/ (3 syllables)
The stressed syllable: marked by an apostrophe: /to'mei·to/
Other information provided is: past and past participle forms (for verbs), comparatives and superlatives (for adjectives), uses, examples...