Different results for same command run from system() vs mac terminal?

I would have expected this R code

system("chromedriver --version") 

[1] "ChromeDriver 78.0.3904.105 (60e2d8774a8151efa6a00b1f358371b1e0e07ee2-refs/branch-heads/3904@{#877})"

to have returned exactly the same result as running the same code from the terminal, i.e.

chromedriver --version

ChromeDriver 2.45.615355 (d5698f682d8b2742017df6c81e0bd8e6a3063189)

but as we can see the results are not the same.

Why does running the same code using system() vs mac terminal yield a different result?