Oracle SQL*Plus
In case you want to access Oracle DB from command line, you can use SQL*Plus.
To install it on Windows, go to Instant client download page and download the Basic Light Package and SQL*Plus Package. Unzip the contents of both packages to a folder and add it to the system path, so you can use the sqlplus alias.
Then you can check if it works by executing sqlplus -v in terminal. If successfully installed, the version will be displayed on the output.