R = ±2e* m how to understand this formula?

Question

assembler

I quote:
Real numbers are represented in the computer in the so-called exponential, or floating, form. The real number r has the form
r = ±2e* m
The representation of the number consists of three elements:
1. sign of the number - plus or minus. Under the sign of the number, one bit is allocated in the binary representation, it is located in the highest, i.e. sign rank. The unit corresponds to the minus sign, i.e. negative number, zero - plus sign. At zero, the sign bit is also zero;
2. exponent e, it is called the order or exponent. The exponent indicates the power of two by which the number is multiplied. The exponent can be either positive or negative (for numbers less than one). The exponent is a fixed number of bits, usually eight or eleven, located in the high part of the binary representation of the number, immediately following the sign bit
3. The mantissa m is a fixed number of bits of the binary notation of a real number in the range from 1 to 2:
That's just me, as a student did not understand anything and there is no explanation in a more mundane language, maybe they can explain everything to me here
PS - this is from the training material "Real variables"

Answer 1

1. I think it's obvious that the most significant bit traditionally indicates whether a number is negative. Zero refers to positive(±).
2-3 should be explained together. The mantissa is the bits of a number, no matter how many there are for calculations, it is considered that it is in the range from 1 to 2, everything else is a fractional part. Let's take a mantissa of 1.5 and multiply by 2. Since the number does not fit into the range, the processor simply adds a power of two (2*e). Now it still stores the number 1.5 in the mantissa to be multiplied by 2 to the first power (2 ¹ * 1.5). If you multiply by 2 again, then it will be in the second degree (2 ² * 1.5), etc. With numbers less than one, the same story 0.25 is the mantissa of 1 times 2 to the minus 2 power (+2 ^-2 *1).