I created a website and uploaded to FTP host and my website was visible on internet. I make some changes to my website and uploaded again to FTP host but I do not see the changes.
We need more details, a link to inspect, etc. If the file uploaded successfully my initial thought is that this is a caching issue but without understanding your issue more it's hard to bbe 100% certain.
I don't think this has anything to do with Dreamweaver. Most likely a browser issue.
Press F5 or Ctrl+R to refresh browser. Or use a different browser. Or clear your browser's cache memory.
In Google Chrome:
Press CTRL/Cmnd + Shift + Delete keys
In Mozilla Firefox:
= Menu > Options > Privacy & Security > Cookies & Site Data > Clear Data.