When you need to transfer a lot of files from one location to another it's sometimes useful to have some progress indication and maybe even a speed measure, or time remaining.
I recently had to transfer a few gigabytes of data from one computer to another. For this task I chose to use Rsync, since it is a command line utility that can preserve file metadata (permissions) and easily resume in case of an error.
Rsync ships with macOS by default, but if you want to get a more recent version, you can install it from homebrew.
There are two options for showing progress:
If you are transferring a few really big files you can use the
rsync -ah --progress source destination
This will list each file as it being transferred and show you the progress and speed in which the file is being transferred.
In my case I had a lot of small files so I chose to use
rsync -ah --info=progress2 source destination
This will output something like this
2.26G 16% 6.13MB/s 0:05:51 (xfr#375313, to-chk=0/1165396)
Which represents the progress, speed and estimated time remaining for the entire transfer.