What is Base units of the SI?

The International System of Units (SI) rests on seven base units: the second ($\mathrm{s}$), the meter ($\mathrm{m}$), the kilogram ($\mathrm{kg}$), the ampere ($\mathrm{A}$), the kelvin ($\mathrm{K}$), the mole ($\mathrm{mol}$) and the candela ($\mathrm{cd}$). Since 2019 each is defined by fixing the numerical value of a constant of nature: the cesium hyperfine frequency $\Delta\nu_{\mathrm{Cs}} = 9\,192\,631\,770\,\mathrm{Hz}$ defines the second; the speed of light $c = 299\,792\,458\,\mathrm{m}/\mathrm{s}$ then defines the meter; the Planck constant $h = 6.626\,070\,15 \times 10^{-34}\,\mathrm{J}\,\mathrm{s}$ defines the kilogram; the elementary charge $e = 1.602\,176\,634 \times 10^{-19}\,\mathrm{C}$ the ampere; the Boltzmann constant $k_B = 1.380\,649 \times 10^{-23}\,\mathrm{J}/\mathrm{K}$ the kelvin; the Avogadro constant $N_A = 6.022\,140\,76 \times 10^{23}\,\mathrm{mol}^{-1}$ the mole; and a fixed luminous efficacy $K_{\mathrm{cd}}$ the candela. Every other unit is a derived unit, a product of powers of base units: $1\,\mathrm{N} = 1\,\mathrm{kg}\,\mathrm{m}/\mathrm{s}^{2}$, $1\,\mathrm{J} = 1\,\mathrm{N}\,\mathrm{m}$, $1\,\mathrm{W} = 1\,\mathrm{J}/\mathrm{s}$, $1\,\mathrm{V} = 1\,\mathrm{W}/\mathrm{A}$, $1\,\mathrm{Pa} = 1\,\mathrm{N}/\mathrm{m}^{2}$.