The PATH and CLASSPATH variables are both environment variables that are used to specify the locations of executable files and Java class files, respectively.
PATH Variable
The PATH variable is used by the operating system to locate executable files (i.e., files that can be run directly, such as .exe or .bat files) when you type a command in the command prompt or terminal. It specifies a list of directories that the operating system should search when looking for a command to run.
CLASSPATH Variable
The CLASSPATH variable, on the other hand, is used by the Java Virtual Machine (JVM) to locate Java class files when running Java programs. It specifies a list of directories and/or JAR files that the JVM should search when looking for a class file that is required by a Java program.
For example, in order to work javac command in the command prompt the PATH variable must point the value of the java executable where it is installed. If it is not set properly then the javac command does not work.
Similarly, when we try to connect MySQL database using the command prompt, it will throw a ClassNotFoundException if the CLASSPATH variable is not set properly to point the location of the mysql-connector.jar file.
In summary, the PATH variable is used to locate executable files, while the CLASSPATH variable is used to locate Java class files.