The domain name will affect how potential customers view your business. You need to have a high quality domain name to ensure the success of your website. You need to make sure that you register a domain name as soon as possible as these domain names can be quickly taken up by people. If you are waiting till the end of the website creation process to choose a domain name, you might not be able to pick the name you want as the chances for it being taken is high.
Most people tend to register a domain name in the very beginning to avoid this issue. This is called domain parking. This is when you register a domain name that is not yet linked to a website or an email hosting service. You are not using this domain actively. This is just to reserve the name until you are ready to use it. What generally happens in creating a parked domain is that you register the name with a domain registrar and link it to a web hosting provider. The web host will store all your website files. The domain name is what directs users to the website. The most common reason for parking a domain is reserving the name as explained above. This can be done before you have a detailed plan on what you are doing with the website. Once the website is created, you can link it to your domain and get it up and running.
There is a phenomenon called cybersquatting which is something that has become prevalent in modern day. This is when somebody registers a domain name that contains a trademark of a big company. When the company is looking for a domain name, it will have already been reserved. The individual who initially registered it will then offer to sell the domain name for a high price. This can be a huge blow to the company as people tend to associate the name of a company with the domain name. And when this cannot be used, people will have a harder time finding the company site. The individual who retains the rights to the domain name can use it maliciously which can tarnish the reputation of your brand. To avoid this happening, a lot of businesses go for parked domains. This way you can protect your name and brand.
You can also register the domain name if you come up with a creative name before the website development is underway. You can then leisurely work on the website without worrying that the domain name will be taken by somebody else. A lot of websites will do this and when a visitor clicks on the link, they will be transferred to a page that says the website is under construction. You can also generate some income from your parked domain by displaying advertisements. When a potential customer visits your site and clicks on an ad, there will be some income generated. You can also wait until the parked domain name is expired if you are not interested in using the name.