studying java concepts

[Abigail Decan]

i'm practicing my programming skills daily, but i'm very unsure about concept questions such as "what is the jvm?" and "what is the difference between a data stream and an object stream?".
on my own, i've found that wiziq has core java concept practice tests.

are there any other resources of you guys' recommendation? thanks

[Jesper de Jong]

"What is ...?" questions can often be answered very well by Google, or by Wikipedia. There is for example a page about the Java Virtual Machine that explains what it is.

Also, Oracle's Java Tutorials covers a lot, from the absolute beginner's Hello World program to advanced things.

If you're studying for an exam such as the Oracle Certified Java Programmer certification, then there are books available which are specifically for people studying for that exam.