Do a google search. Sorry, not being smart, but all the info is there.
In a nutshell
Laptop - will run Windows OS and have a hard drive. Will run all standard windows applications. Think portable desktop. Lower battery life
Chromebook - Will run on google chrome. Is really an internet browser made flesh. Will run for a day on batteries and is a lot lighter. No hard drive, so is really only useful for web surfing. It boots up faster. You can write document and store them on line. It really needs either wifi or if available, mobile phone signal (3G) to be of any use. Will be a lot cheaper than a laptop.
This is a very cutdown version of the differences. Again, all the info is on line.
In summary, if all, or the majority ( >90%) of your use is internet based, then a chromebook is a runner. If you need other software and/or a lot of documents, then a laptop might be a better proposition.