  We use brane techniques to study the space of vacua of abelian 3d
$\mathcal{N}=3$ gauge theories. The coordinates on these spaces are the vevs of
chiral monopole and meson operators, which are realized in the type IIB brane
configuration of the theory by adding semi-infinite $(1,k)$ strings or F1
strings. The study of various brane setups allows us to determine a basis of
chiral operators and chiral ring relations relevant to each branch of vacua,
leading to the algebraic description of these branches. The method is mostly
graphical and does not require actual computations. We apply it and provide
explicit results in various examples. For linear quivers we find that the space
of vacua has in general a collection of Coulomb-like branches, a Higgs branch
and mixed branches. For circular quivers we find an extra branch, the geometric
branch, parametrized by monopoles with equal magnetic charges in all $U(1)$
nodes and meson operators. We explain how to include FI and mass deformations.
We also study $\mathcal{N}=3$ theories realized with $(p,q)$ 5-branes.
