If will a high bitrate video be easier or harder on a video editor than a low bitrate video?
The above answer by Adam is not really accurate...
There are different bottlenecks to consider.
Bitrate x Time = Size of File. means Higher Bitrate requires Faster Hard Drives
Compression / Codec / Ratio of Compression is either processor intensive, gpu processor intensive, or both (depending on your GPU/editing software). Adobe for example, makes use of NVidia's CUDA cores for faster decompression and encoding of compressed files.
High Bitrate, such as lossless, uncompressed, etc, will require high throughput (Fast Hard Disks, from SSD to SAS RAID/Etc) to handle the data rate of the video file to play in real time.
However, uncompressed video requires less CPU processing power, because the CPU does not have to "uncompress" the file.
If you are editing for example, H.264, highly compressed at a variable bit rate, your bottle neck would be your CPU and GPU (if you are using a system which uses your GPU for video overlay output).
In general: If you have a fast RAID HDD setup, editing uncompressed is far smoother, more responsive, quicker to render especially, than working with a compressed codec. EVEN with a slower CPU/GPU - simply because the CPU/GPU does very little work / calculations to decode the file.
If you are working off a single spinning drive, you'll be limited to the 110 MB/s bottleneck (bi directional) so having a faster CPU and GPU would be the way to go with compressed files.
If you have 2 SSD's of equal size, and can SATA port them to your Motherboard, create a RAID 0 and you should get roughly 1 GB/S read speed. I have 4 SSDs in RAID ZERO on an Intel RAID card, and get 4 GB/s - zero lag at all.
Bitrate is the amount of information contained in the video file. now I think the question is a bit vague. I assume you mean which will affect your computer more for editing.
More bitrate will mean a more beefy computer (CPU, GPU and HDD passthrough) to edit so it can handle the files.
Now if you have a high bitrate file and it is struggeling to play due to computer specs you can convert it to a proxy file which is a low bitrate of the file to make it easier to edit and then relink it later to the high bitrate file for final export.
Hope that helps