What is the meaning of the -XX:NewRatio and -XX:OldSize JVM flags?

I am starting my java app with the following command line :

java -XX:+PrintCommandLineFlags -verbose:gc -XX:+PrintGCDetails \
     -XX:+UseConcMarkSweepGC -jar start.jar

The JVM enables the following options:

-XX:MaxNewSize=87244800 -XX:MaxTenuringThreshold=4 -XX:NewRatio=7
-XX:NewSize=21811200 -XX:OldPLABSize=16 -XX:OldSize=65433600
-XX:+PrintCommandLineFlags -XX:+PrintGC -XX:+PrintGCDetails
-XX:+UseCompressedOops -XX:+UseConcMarkSweepGC -XX:+UseParNewGC

Can anyone explains me the meaning of NewRatio and OldSize ? In particular OldSize is the initial size of the tenured generation ?