Hi Abdul,
cannot answer what SAP HANA is in just 3 sentences 
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However, boldly speaking, HANA is - at the very core - a database. And just like all SAP supported/certified databases, you can access HANA via OpenSQL (at least if you're working with an AS ABAP 7.31 or higher release, or best, to run on AS ABAP 7.4) .
When "normal ABAP syntax" means OpenSQL, yes, you can use it 
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But having said this, HANA is more then just a database. If you would like to learn more about HANA, visit, e.g. the OpenSAP course by Vishal Sikka Course: An Introduction to SAP HANA by Dr. Vishal Sikka or the SAP HANA Developer Center .
And if you have specific questions on ABAP for SAP HANA, just ask us!
Cheers,
Jasmin