In our environment the following entries are discovered. The link 'https://dzone.com/articles/how-to-choose-a-hadoop-distribution-understanding' shows these are some kind of HDP packages.
2. Can these be downloaded separately and installed?
I don't seem to find any information regarding these packages. Any help would be appreciated.
I have posted the answer to the other question you have asked. here posting it again.
there are HDPs hadoop packages. you can install directly using repo URLs. please follow the installation steps given at https://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.6.5/index.html
Please note that above packages you mentioned are 2.4.2 which is old, you can go with HDP2.6.5/3.0
Installing these packages/services with Ambari would be much simpler.
Note: Please mark this as correct answer if you satisfied with explanation.