How does InputStream vs Reader impact performance or memory usage?

In Java, the difference between InputStream and Reader can significantly impact performance and memory usage, especially when dealing with character and byte data. InputStream is designed for reading raw byte streams, while Reader is tailored for reading character streams. This distinction influences how data is processed in an application, particularly with regards to handling encoding and decoding of text.

When you use InputStream, you're dealing with bytes directly, which can be more efficient for binary data (such as images or audio files). However, when working with character data (like text files), using Reader can simplify handling character encoding by automatically translating bytes into characters based on a specified charset.

Using InputStream may lead to additional overhead in terms of converting byte data to character data, potentially affecting performance if your application heavily deals with text. On the other hand, using Reader can minimize this overhead, providing better performance when processing character data while also utilizing memory more efficiently when dealing with strings in different character sets.