Some Questions about domains

I have an idea for a domain name, but what happens if you want to change it later? Would you completely lose your search rankings?

Or if you have made one website, and you wish to incorporate it into a larger website, could you do this without losing search engine placings?

Thanks!

 

Use 301 redirect from old domain to new one and everything will be ok.

 

Make sure that you don't lose your previous domain i.e you have to have two domain names. Visitors will be redirected to newer url as soon as they land on old one.

 

through 301 redirect, you will lose your ranking but after 4 to5 months it will recover.