Its based on from which file you are trying to access those files.
If it is in the same folder where your working project file is, then you can use just the file name. no need of path.
If it is in the another folder which is under the same parent folder of your working project file then you can use location like in the following /javascript/sample.js
In your example if you are trying to access your js file from your html file you can use the following location
../javascript/sample.js
the prefix../ will go to the parent folder of the file(Folder upward journey)