If the need arrises that you would have to give access to a developer for them to build or make updates on your sites there are a few option for you on how they are going to gain access to your website. Before we get started one thing we recommend when providing access to your site to anyone is that you should always make of backup of your site and download it to your local computer. This ways if anything happens to your site you are able to restore your site before they made those changes. Another thing to keep in mind is to never provide your login credentials for the billing portal since this gives complete control over your entire Create account and they may lock you out of the account.
The most common way to provide access to a developer is to provide them access to cPanel since this will provided them complete access to everything that they may need to build the website. The main thing that this allows them to do is install which ever website building tool that they need to have installed on your domain. This option will also provide access to all of your sites that is under the the cPanel, so this option is not recommended if you host multiple sites and you only want to give access to a single site. If you plan to give access through cPanel keep in mind that there is only one login username and password but you have access to change that password at anytime with in your billing portal.
Another option is to create a user for the developer with in the content management system (CMS) that gives them access to the managing tools of the site. This option will only give access to that one single website's developing tools and use the same log in link that you would use to login. An example of this is WordPress, this cms gives you an option to create as many users that you'd like and limit the access of each user. Keep in mind some cms may not have this option available.
File Transfer Protocol (FTP) will allow someone to upload and download files of your site. This method would mainly be used if the developer has built the site on their local computer and they need a way to upload the site files over to our server. This will also allow them to change the coding of the site if they need to make those type of updates.You are able to choose how much access they will have to your site files. One option is to only provide access to a single site or to all of your sites.