Distros : Prep - wget
Wget is an easy to use command line tool for downloading files, its a better option than using a web browser.
At the Download Page of a Linux Distro, below is one of Debian's Network Install pages, there will be the installation image, that's the .ISO file.
There should also be a method of verifying this image in the form of a checksum file, the SHA256SUMS and SHA512SUMS files and signature files the .sign files, more of them later, for now as they are small text files simply Right Click and Save As placing them into your Download Folder

Ideally Click on Create Folder and name it after the Linux Distro, (this could be the first of many Distro that you try out). I created a folder - Debian11 and saved the files there.

Now to download the much larger .iso file. Open a Terminal and change directory cd
to where you have downloaded the files and do an ls
to see them.
$ cd Downloads/Debian11/ Dow then Tab then D then Tab $ pwd /home/bryan/Downloads/Debian11 $ ls SHA512SUMS.sign SHA512SUMS
Back at the download page Right Click the link for the .iso file and this time choose to Copy Link Location instead of Save Link as.

Returning to the terminal type in wget and space
then Right Click and choose Paste or better still just do a Ctrl+Shift+V to give wget the link for the ISO and hit Enter.

$ wget https://cdimage.debian.org/cdimage/unofficial/non-free/cd-including- firmware/current/multi-arch/iso-cd/firmware-11.0.0-amd64-i386-netinst.iso
wget will do some Resolving and Connect to a server making a HTTP request and then start to download fhe file.

Wget has many download options the most important option is -c or --continue if you like typing, to resume a partially downloaded file. To try it out I stopped wget with Ctrl+C.
$ wget --help ....... Download: -t, --tries=NUMBER set number of retries to NUMBER (0 unlimits) --retry-connrefused retry even if connection is refused --retry-on-http-error=ERRORS comma-separated list of HTTP errors to retry -O, --output-document=FILE write documents to FILE -nc, --no-clobber skip downloads that would download to existing files (overwriting them) --no-netrc don't try to obtain credentials from .netrc -c, --continue resume getting a partially-downloaded file --start-pos=OFFSET start downloading from zero-based position OFFSET --progress=TYPE select progress gauge type --show-progress display the progress bar in any verbosity mode -N, --timestamping don't re-retrieve files unless newer than local .....
I then hit the Up arrow key to go back to the wget command, hit the End key to get to the end of that command, added a space then added the -c option and hit Enter to continue the download.

The +++ signs indicates the amount of file previously downloaded and the ===> indicates the latest progress.
I did Ctrl+C a few more times and then the -c option to resume, and when the file downloaded I proved it was perfect by running the command sha512sum -c SHA512SUMS.
$ ls firmware-11.0.0-amd64-i386-netinst.iso SHA256SUMS.sign SHA512SUMS $ sha512sum -c SHA512SUMS This command took over a minute to complete!! firmware-11.0.0-amd64-i386-netinst.iso: OK
Now to prove that the Checksum file was created by Debian and so proving that they created the .iso file: I have gpg set up on my pc so I simply issued the command below..
$ gpg --verify SHA512SUMS.sign SHA512SUMS gpg: Signature made Sat 14 Aug 2021 21:26:26 BST gpg: using RSA key DF9B9C49EAA9298432589D76DA87E80D6294BE9B gpg: Good signature from Debian CD signing key debian-cd@lists.debian.org [full]
While still in the Debian11 directory I could go old school and use dd to burn the ISO onto a USB Key or play it safe, go back to the Desktop and use Etcher instead.