Instant Client is a free-to-download, lightweight Oracle database client designed to allow you to run your applications without installing the standard Oracle client or having an ORACLE_HOME. You can use it in place of the standard Oracle client when using Database Connectors for Oracle.
Setting up Oracle Instant Client can be challenging and should be performed by advanced users only. You will need the Basic Lite and SQL*Plus packages, available from the Oracle web site. Follow Oracle's instructions to install and configure the products.
If you also installed the SCOTT/Tiger test schema, you can test the connection to the Oracle database using SQL*Plus before proceeding with the Database Connectors client install.