Help Please!

Does anyone recognize this stitch? I don’t even know if it is knit or crochet! And how are the colors done? Any help would be appreciated! Thank you.

It’s seed st alternating colors with each st and 2 rows with each color:green and white, green and black, white and black, white and green, black and green, black and white.

so it’s a knit stitch?

Seed stitch is alternating knit and purl sts, similar to k1 p1 ribbing, but offset by a stitch. See the video for it under Basic Stitches on the Tips page. The purls give you that bump.