galois theory - Relation between field extensions generated by the different roots of a given irreducible polynomial

Consider an $n$-degree irreducible polynomial $f(x)$ on $\mathbb{Q}$. Generally, it has $n$ different roots in $\mathbb{C}$. Denote them as $\{ \alpha_1, \alpha_2, \ldots, \alpha_n \}$. Each of the roots can generate a simple extension of $\mathbb{Q}$, i.e., $\mathbb{Q}(\alpha_i )$ with $1\leq i \leq n$.

The problem is, what is the relation between these $n$ field extensions?