That A34 5G uses MediaTek's Dimensity 1080 and the Samsung A54 5G has that Exynos 1380, which apparently offers a slight performance boost in early benchmarking. 

Both of these mid-range smartphones serve up a familiar S23 design, although the A34 is larger at 6.6 inches vs 6.4. The Samsung Galaxy A54 5G upgrades the back to Gorilla Glass 5, while both are water resistant.

That camera tech is completely different, however. You get a larger sensor with bigger pixels on the Samsung A54, for improved low-light photography. 

The Samsung Galaxy A54 5G may sport a smaller display but it's the same slick Super AMOLED tech with 120Hz refresh and 1000 nits brightness. You have a stereo speaker setup, microSD support, and years of OS updates too.