I have a question about serial communications.

Hello. I'd like to ask you about serial communications.

I'm trying to print the value of the current ADC on a serial monitor using the Serial.print() function.

I'll google it. Serial.From Begin (speed, config), I found that config's default settings are 8 data, no parity, and 1 stop bit.
I understand that when you print out a value on a serial monitor, you can only express it up to eight bits.
If it's eight bits, you'll only be able to print numbers from 0 to 256 in the Serial.print function, but the short type and the range of values are the same. After 32,767, there was an overflow, and any negative value was output.
I really want to know why. It's so strange that I think I misunderstood the data on the Internet.

And...
The current code receives the ADC value of 10 bits, and stores the ADC value in the float type variable and outputs it on the serial monitor.
I know that we need to send 8 bits for serial communication, so I'm going to change the float type to the 8-bit data type, the Char type.
When I googled it, is it possible to change it from float type to char type, or is it a problem that can be solved by just changing the shape?
I have a question here. If the ADC value is 1023, is it printed as 255 instead of 1023 when the shape is changed to Char?

Thank you for reading it. Please give me an answer.

the Serial interface transmits data in bytes. This accommodates ASCII characters

you could transmit raw binary values using write() which means you need to send two bytes to represent an adc value of 1023 and which also means you need some way to synchronize to the pair of bytes being transmitted

you can also send the adc value as an ascii string with a newline terminator println(). You could then use readStringUntil('\n'); to read a complete value.

void setup() {
  Serial.begin(9600);

}

void loop() {
    String s;

    if (Serial.available())  {
        s = Serial.readStringUntil ('\n');
        Serial.println (s);
    }
}

01037839648:
I'm trying to print the value of the current ADC on a serial monitor using the Serial.print() function.

I'll google it. Serial.From Begin (speed, config), I found that config's default settings are 8 data, no parity, and 1 stop bit. [........]

If you are literally just trying to print the value as a human readable string on a serial monitor, something like
Serial.print(analogRead(A0)); will work, and all that worrying about serial transmission details is not relevant.

You may be confusing Serial.print() with Serial.write(), which does emit binary format.

The current code receives the ADC value of 10 bits, and stores the ADC value in the float type variable

Why store ten bits of integer in 32 bits of float?