In the United States, the TLD for government domain names is .gov
A website domain is traditionally known as the name or URL of a website
According to the website the Australian government funds and also operates this page. This can also be seen by the domain of that website which actually indicates a "Government" domain.
You need both for online presence of your business. Domain name is just like the address/location of your business on the web. When we type your domain name on our browser, it goes to your website. Website is more of a group of files that you show to your online visitors. You have a domain name but no website - what's the purpose of having your domain name? You have a website but no domain name - how can people see your website? The two things need to go together for online presence of your business.
Usually the person or company who purchased the domain name that is used to access the website. Without a domain name a website is not accessible from the internet. You can also specify who the owner is when purchasing the domain name.
When a domain is seized, it means that the government or law enforcement agency has taken control of the domain name and website associated with it, usually due to illegal activities or violations of laws.
A domain host functions as a host for your website. For example if you want a website for your company, you will require a domain host in order to set up a domain for your website. Often you can purchase a domain name that matches the name of your company.
GoDaddy is one website that checks the availability of domain names online. One can sign up on this website and they will inform you whether a domain name is available.
Usually the person or company who purchased the domain name that is used to access the website. Without a domain name a website is not accessible from the internet. You can also specify who the owner is when purchasing the domain name.
Domain name resellers open a website under a domain name and then hold the domain until some purchases it. This is done so that companies can get a domain that makes sense for the name of their business and avoid other people posing as their website.
A ch domain name refers to a Switzerland based website. "CH" is derived from the Latin name of the country. One would use this domain name for a Switzerland based website.
Domain name lookup lets you see whether a particular website name (the domain) has already been bought by someone. If so, it shows you who is the registered owner of that particular website name (the domain), their address, and until when they own it.
If you are planning to build a website and you need an idea for a domain name, websites such as Go Daddy can help. The official Go Daddy website has a domain checker where you can see if the domain is available.