Firstly, Java is a statically-typed language, which means that you need to declare the data type of a variable when you create it. Python, on the other hand, is dynamically-typed, which means that the interpreter automatically detects the data type based on the value assigned to the variable. This can make Python code easier to write and read, but may lead to some runtime errors that could have been caught at compile time in Java.
Secondly, Java is generally faster than Python, as it compiles to bytecode and runs on the Java Virtual Machine (JVM), while Python is interpreted. This can be an important factor when performance is critical for your application.
Thirdly, Java has a more complex syntax compared to Python's simpler and more readable syntax. This can make Java code more difficult to write and maintain, but also provides more control over the code and its execution.
Regarding when to use each language, I would say that Java is well-suited for large-scale, enterprise-level applications, especially where performance is a concern. It has a strong ecosystem and robust libraries, making it an excellent choice for building complex, high-performance systems.
Python, on the other hand, is a great choice for smaller projects, rapid prototyping, and data analysis. Its readability and simplicity make it easy to learn, and its extensive library support makes it great for tasks like web development, scripting, and machine learning.