
Samsung Galaxy
The latest firmware for Samsung Galaxy (SM-G530A) is G530AUCS4AOID, released on May 3, 2017 for 1 region (CSC). Every official firmware build for SM-G530A, newest first: one row per build with all regions (CSC) that received it.
Each firmware build has its own page at https://samfirm.shop/build/{PDA}, where {PDA} is the build number from the list above. Example: https://samfirm.shop/build/G530AUCS4AOID
The newest build, G530AUCS4AOID, was released on May 3, 2017. No new build has appeared for 115 months, so regular updates for this model have most likely ended.
Specifications of SM-G530, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

SM-G530AZ

SM-G532MT

SM-G525N

SM-G6200

SM-G730V
The latest build for SM-G530A, G530AUCS4AOID, was released on May 3, 2017 (9 years ago).
SM-G530A has had no new firmware for 115 months, so regular updates have most likely ended.
Yes, all firmware files for SM-G530A are 100% official, original, and obtained directly from Samsung servers.
To flash SM-G530A, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SM-G530A.