Here's a picture to clear a few things from OI
Price action is an important indicator to determine accumulation or writing
ACCUMULATION
If OPEN INTEREST increases and the price also increase, it suggests that accumulation is taking place.
WRITING
If OPEN INTEREST increases and the price decreases, it suggests that writing has been done.
As writers play with limited profit and unlimited loss potential, they have a larger stake... so a higher OI at any level indicates more conviction by those traders that price wouldnt go above those levels...
So a call writer is a bearish player and Put writer is bullish
Hope this clears things up and we can move onto trading