The Oracle Call Interface (OCI) is an application programming interface to Oracle RDBMSs. It consists of a library of C language routines to allow C programs (and in some cases programs written in other third generation languages) to send SQL statements to the database and interact with it in other ways.
Oracle's JDBC/OCI drivers provide an implementation of the JDBC interfaces. This implementation uses the OCI to interact with an Oracle database. You must use a JDBC/OCI driver appropriate to the Oracle RDBMS you wish to access. The Oracle JDBC/OCI7 driver works with Oracle7. It allows you to call the OCI directly from Java.
The Oracle JDBC/OCI7 driver is not appropriate for Java applets, because it uses a C library that is not downloadable by a Web browser.
Java applications and Java code running in the Java cartridge must explicitly load the JDBC/OCI7 driver before using the JDBC entrypoints. See "Using Oracle's JDBC/OCI7" on page -5 for details of how to do this.