A file's read position, also known as the file pointer, is a location indicator that determines the current position for reading data from a file.

• It represents the offset or byte position within the file where the next read operation will occur.
• When you read data from a file, the read position moves forward, indicating the location of the next byte to be read. 
• In most programming languages, when you open a file for reading, the initial read position is set to the beginning of the file.
• This means that the first read operation will read data starting from the first byte of the file. The read position is set to 0 (zero) for the first byte, and it increases as more data is read from the file.

For example, consider a text file with the following content:

Hello, this is a sample file.

• If you open this file for reading, the read position will be at the beginning of the file (i.e., before the letter 'H'). When you perform a read operation, the content "Hello, this is a sample file." will be read from the file, and the read position will move to the end of the file (i.e., after the last letter 'e').
• If you perform another read operation after the first one, it will return an empty string or signal the end-of-file (EOF) condition, as the read position is now at the end of the file.
• It is essential to manage the read position properly when reading from files, especially when using random access techniques or when seeking to specific locations within the file for efficient data retrieval. In most cases, sequential access from the beginning of the file is the default and simplest way to read data from a file.