OneDrive comes pre-installed on Windows 10. It won't sign you in even if your PC is linked to your Microsoft account but once you do sign in, it by default puts your OneDrive folder at the root of your User folder. OneDrive will then sync files to that folder and depending on how big and how many files you've synced, it might take up substantial space on your hard drive.
If you prefer to move the files to a different drive and change where OneDrive saves files, simply right-click on the OneDrive icon in the System Tray and select 'Settings', then unlink OneDrive from the PC. Open your OneDrive folder at its location then de-select it and move it to a new place using the 'Move to' button at the very top of the Home tab in the Explorer ribbon. Next, sign in to OneDrive again. When you sign in, OneDrive will ask you where you want to save folders to with a suggested location already selected. Instead of accepting this suggested location, click 'Change' then navigate to where you moved the OneDrive folder to.