npm ci --force vs yarn - don't understand enough what's these command do :)

 Today was installing app dependencies using yarn and npm.

When i do a "npm install" it keeps on saying I need to resolve some dependencies. 

Then tried using npm ci --force it works.

npm ci is used specifically for an automated or ci environment where there will be less interactivity.

--force: will force npm to fetch remote resources even if a local copy exists on disk.