Hi Esteban,
There are many differences between Biblical and Modern Hebrew.
Biblical Hebrew is old and not used daily, however, Modern Hebrew contains slang and words from other languages such as: Arabic, English, German etc.
For example:
In order to say say "Shalom" in Biblical Hebrew you will say: "שלום עליכם" - Shlom Aleychem" and in Modern Hebrew you will just say - שלום or Hi.