Difference Between Oracle lnstant Client and Oracle Client
Oracle client comes with an installer and a lot of executable likesqlplus, tnsping, it's complete and huge.
Oracle Instant client is a basic lightweight client which can beunzipped in a location without any installation, it contains only thecommunication layer to be able to connect to oracle. It can beextended by adding for example sqlplus which ships as a separateexecutable. When using Instant Client, just unzip it to a location,set your ORACLE_HOME environment variable to this location and youare ready to go.