Question About Definition of a Topological Space

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I believe the following definition is correct for a topological space. However, the book I am using refers to just $X$ being a topological space later on down the road which I am confused with.

$\textbf{Question about Terminology:}$ Is the topological space $(X, \tau)$ really the set $X$? I would have thought it would have been $\tau$. I assume the two tuple here acts similar to that of a groupoid where it is really just a set but I could be wrong.

$\textbf{Definition:}$ Let $X$ be a non-empty set. Also, let $\tau=\lbrace O_i\subseteq X| i\in I\rbrace$ ($O$ signifies these sets are open, i.e. not necessarily open in the context of metric spaces).

We say $(X, \tau)$ is a $\textbf{topological space}$ iff the following conditions are satisfied:

$(C1)$ $\phi, X\in \tau$

$(C2)$ $\forall J \subseteq I$, [if $J$ is finite, then $\cap_{j\in J} O_j\in \tau$]

$(C3)$ $\forall K \subseteq I$, $\cup_{k\in K} O_k \in \tau$.

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Formally, the topological space is the pair $(X, \tau)$ with $\tau$ the collection of open sets that obey the axioms. But the $X$ is important too, as it provides the context: all open sets are subsets of $X$ (and we know that $X \in \tau$ too).

$\tau$ is called a "topology on $X$", and the pair together a "topological space".

It is common practice to omit the $\tau$ and consider it understood in "the topological space $X$". The context must make clear what topology $\tau$ is actually meant. In measure theory the same is often done and the $\sigma$-algebra is also understood from context (the pair of set $X$ and $\sigma$-algebra is then a "measurable space"). Likewise with metric space (this includes the $d$, so is also a pair $(X,d)$) and a uniform space.

In algebra you also say the "ring $\mathbb{Z}$" instead of the more formal "ring $(\mathbb{Z}, +, \times, 0, 1)$" etc. Only when we want to be extra precise or when we have different structures on the same set, the extra structure is emphasised this way, usually.

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You're correct that it's the topology on the set that really matters, not the set itself, because the same set can have very different topologies on it. However, we usually refer to it by just the set because it's notationally convenient and the topology is often implicit. When I say "Let $ X $ be a topological space", we know that we're putting some topology on $ X $, but we choose not to give it a name. Furthermore, when we're given a space like $ \mathbb R $ there is often a specific topology we normally consider, like the Euclidean topology.