A note's duration is indicated by ​

In music its  a note value indicates the relative duration of a note, using the texture or shape of the notehead, the presence or absence of a stem, and the presence or absence of flags/beams/hooks/tails. Unmodified note values are fractional powers of two, for example one, one-half, one fourth, etc.

Explanation:

answer: to accurately look up a word in the dictionary, look at the letters until it comes close to the word, then on that page you will find it and learn the word. a dictionary will have words similar such as its synonyms and its roots, but also how to pronounce the word and it's roots. a dictionary is when making sure you're using the right word in a writing piece or just when you need clarification what the word is/means.

explanation: i hope this is as it is also self explanatory. have a wonderful day and i hope this you! < 3