basically there are two definition of batik:
1. the process (the wax painting, the multiple dyeing process - or the “chop” batik)
2. the pattern
Number one is undoubtedly batik (”banyak titik” lots of dots, haha) - but this is expensive and only some Javanese would bother to own it and maybe some batik aficionados. My late grandmother would paint her own batiks… and she’ll send it to the dyers. it’s a tedious process. The second is the most common - usually the batik, or the painting, it can be stylized flowers, or animals such as birds and dragons… printed on cotton or silk or rayon. There are a lot of “modernized” prints now - most Indonesians would know which pattern is considered batiks… Traditional pattern represent more than meets the eye… it has ‘powers’ to aid the wearer of the cloth - so it has its own designation, for example, for weddings of a family members we know which pattern we should wear. Facebook has a group dedicated to batik fans “I Love Batik” - look for it!

btw, the photo above shows the non-batiks… maybe it’s malaysian batik, but definitely not Indonesian/Javanese batik.

any idea how to differentiate? and where to get genuine one?

I heard from my friends the price of batik starts from 16000 - 4mill. rupiahs.
Happy shopping!