When NaBr dissolves in water, it breaks up into its component ions, Na+ and Br-. The Na+ ions are positively charged, while the Br- ions are negatively charged. The attraction between the positive and negative ions is what holds the compound together in its solid state. However, when the compound is dissolved in water, the water molecules surround the ions and break apart the crystal lattice. This allows the ions to move freely in solution.

The equation for the dissociation of NaBr in water is:

$$NaBr_{(s)} \rightarrow Na^+_{(aq)} + Br^-_{(aq)}$$