• A package is a group of class files.
• Packages help organize your code.
• Packages help keep your code unique from other people so you can resolve conflicts in your code if you have two or more classes with the same name.

// after your website
package com.site.packagename;
package net.site.packagename;
package org.site.packagename;

// using your initials and/or company name
package jre.packagename
package jre.companyname.packagename;

Generic.

javac -d c:/path/to/compile/to c:/path/of/source/file.java

Generic, compile all java files in a directory.

javac -d c:/path/to/compile/to c:/path/of/source/*.java

Current directory = './' or simply just '.' so all these are the same.

javac -d ./ ./*.java 

javac -d . ./*.java

javac -d . *.java

Compiling from two sources.

javac -d ./ ./source1/*.java ./source2/*.java

If in different directory.

java -cp c:\location\of\packages full.packagename.ClassName

If in the package directory.

java full.packagename.ClassName

c:/location/of/source/files/update-sources.cmd

dir /s /b *.java > sources.txt

Compiles all your java files to the current directory.

javac -d ./ @sources.txt

Compiles all your java files to a folder called bin, in the current directory.

javac -d ./bin @sources.txt