Let $U,W$ be [[vector space|vector spaces]] over [[field]] $K$
The **direct product**, the set containing [[tuple|tuples]] $(u,w)$ from the spaces $U$ and $W$, is $U\times W$
$U\times W = \set{(u,w):u\in U\ \land \ w\in W}$
Tuples from the product can be added
$\left(u_{1}, w_{1}\right)+\left(u_{2}, w_{2}\right)=\left(u_{1}+u_{2}, w_{1}+w_{2}\right)$
And they can be scaled for $c \in K$
$
c\left(u_{1}, w_{1}\right)=\left(c u_{1}, c w_{1}\right)
$
Since both spaces contain a zero vector
$(\mathbf0,\mathbf0)\in\ U\times W$
Which works as an additive identity.
So this direct product works as its own vector space
In the case that a **direct product** is taken of a [[set]] of $n$ vector spaces
$\begin{aligned}\prod_{i=1}^{n} W_{i}&=W_{1} \times \cdots \times W_{n}\\&=\set{\left(w_{1}, \ldots, w_{n}\right): w_{i} \in W_{i}}\end{aligned}$