I have about a dozen or more paperback and hard cover dictionaries. They sit on my shelf a few feet away. They contain thousands, possibly millions, of words that will help me write a story.
But sometimes I’m lazy, and I don’t want to get up. Sometimes I have my feet soaking in warm water and essential oils, so I can’t get up without making a mess. Sometimes I need to check on current changes to spelling and grammar use.
So sometimes, I use an online dictionary. There are many, and you don’t have to settle on one. Almost all are free.