The Beretta is recommended for weaker enemies such as zombies and Cerberuses and tends to be useless against stronger enemies such as the Hunters due to its limited stopping power.
In Resident Evil: The Director's Cut and all subsequent re-releases of the game (including Resident Evil: Deadly Silence), the original black beretta is replaced with a chrome-plated custom variant. It is fundamentally the same gun, save for a different model, menu icon, and the fact that it now possesses a small chance to instantly kill a Zombie with a critical hit. This makes the starting handgun a much better weapon early on and lets it maintain its use for much longer.
In the 2002 remake, this weapon is replaced by its modified variant, the Beretta 92F Custom 'Samurai Edge'. It retains the ability to score critical hits from the Director's Cut version.
"Beretta M92FS. Automatic loaded with 9mm bullets."