An FTP account is used for uploading and managing files on your website, you can create multiple FTP accounts and allow them access on desired folder so they cannot have access on other files/folders in your cPanel.
Step 1. Log in to the cPanel.
Step 2. Under Files panel, click on "FTP Accounts"
Step 3. Enter desired username, password and the new directory or path of existing directory. Once done, click on Create "FTP Account" button.
There are multiple FTP clients that can be used to connect the FTP server. However FileZilla Client is highly recommended. Just make sure, you have the correct FTP credentials.