1. Bootcamp

less processor intensive, because it works via dual boot - ie you restart your mac and choose a different boot option, and only have one OS running at a time
cheaper, because you only have to buy Windows 10 (£99 in Feb 2021)
more awkward - you have to restart your laptop to change OS
more faff to install. There’s a great guide, but there are a lot of steps and you need a separate browser open on a separate device to follow instructions and install at same time
fixed disk size. You have to decide disk size in advance and it creates a new partition, so (I think) you then get reduced disk size in both OSes.
Harder to share files between OSes. You would basically have to download files from the cloud for each separate OS. Each partition doesn’t have access to the other one.

2. Parallels

more processor intensive: will run a virtual machine hosted by OSX, so both OSes are running at once. But if you have 8Gb more of RAM (“memory” in About This Mac) you should be fine.
more expensive - you have to buy Parallels (currently £80 in Feb ‘21) as well as Windows 10
less awkward - you can easily switch between OSes
easier to install - it’s just another piece of software
variable disk size - you can reconfigure at any time
easier to share files between OSes.