What is the meaning of parentheses in "NAD(P)H"?
If an enzyme is called $\mathrm{NAD(P)H}$-dependent, that means it is using both $\mathrm{NAD^+/NADH}$ and $\mathrm{NADP^+/NADPH}$ as its cofactors. For example, most oxidoreductases are $\mathrm{NAD(P)H}$-dependent, which are able to oxidize a relevant substrate by transferring a hydride ($\ce{H−}$) group to a nicotinamide adenine dinucleotide cofactor (either $\mathrm{NAD^+}$ or $\mathrm{NADP^+}$), resulting in their reduced forms, $\mathrm{NADH}$ or $\mathrm{NADPH}$ (Ref.1):



You can find a list of $\mathrm{NAD(P)H}$-dependent oxidoreductases within Reference 1.



Reference:


Lara Sellés Vidal, Ciarán L. Kelly, Paweł M. Mordaka, John T. Heap, "Review of NAD(P)H-dependent oxidoreductases: Properties, engineering and application," Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics 2018, 1866(2), 327-347 (https://doi.org/10.1016/j.bbapap.2017.11.005).