The Apache Tomcat Native Library is an optional component for use with Apache Tomcat that allows Tomcat to use certain native resources for performance, compatibility, etc.
Specifically, the Apache Tomcat Native Library gives Tomcat access to the Apache Portable Runtime (APR) library’s network connection (socket) implementation and random-number generator. See the Apache Tomcat documentation for more information on how to configure Tomcat to use the APR connector.
Features of the APR connector:
Non-blocking I/O for Keep-Alive requests (between requests)
Uses OpenSSL for TLS/SSL capabilities (if supported by linked APR library)
FIPS 140-2 support for TLS/SSL (if supported by linked OpenSSL library)