There is often a discussion of

<div style="display: inline">

being able to make a block element into an inline element.

so is it true that

<div style="display: inline">
[any possible markup here...]
</div>

is *identical* to

<span>
[any possible markup here...]
<span>

and vice versa,

is <span style="display: block"> identical to a <div>?

please, if you could, indicate whether this is your opinion, like from
some years of experience, or whether there is a reference documenting
that it is true? thanks so much.