Ethernet bit rate

[radiolistener]

There is no such thing as "infinite amount of information" since information is entropy and entropy is a finite quantity determined by chemistry and physics.

if it's finite, then what is the quantum of time, what is the quantum of voltage and what is the quantum of frequency?

it's impossible to capture analog signal with all details, because it requires storage with infinite capacity to store such signal representation. The noise in analog signal is also a part of information.

With digital signal you can do that, you can capture it and replay it again with all details.

[radiolistener]

Please explain how logic thresholds are not 'analog' in your view of the world

The digital signal is digital not because there is logic thresholds, but because it is discrete and represents data in a form of binary digits. The digital signal is discrete in amplitude and discrete in time. It is not continuous like analog one. The logic threshold just define valid range for discrete level. The same there is time threshold which define time interval when digital signal is valid.

The digital component is intended to work with discrete binary digits.
The analog component is intended to work with continuous waves...

Is an NRZ-I signal digital to you?

yes, it is digital, because it is discrete in amplitude - logic 0 or 1 and discrete in time.

How about a Manchester code?

it also digital, becuase it is discrete in amplitude - logic 0 or 1 and discrete in time. Despite the fact that it don't use plain clock, it still has some clock with constraints.

For comparison 1000BASE-T is analog sum of two PAM5 streams (RX and TX) clocked form two different and async clocks.

And each of PAM5 streams can have 5 levels, which is also not digital according to the definition of the term "digital" from the cambridge dictionary which I quoted above (digital signal is represented with two levels 1 or 0).