Newbie here... have some white patches on my orchid?

[Bulltart]

Firstly, hi all!

I am very very new to this, so please bear with my ignorance. I am quite interested to learn more about this plant and how to take care of it.

Over the past years, I've bought my wife some orchids... we now have five plants. Nothing super exotic.

We've noticed that these plants are survivors, and grow flowers over the years.

One of our plants has sprouted a stalk again, but there is a white patch on its leaf. I have no idea what it is, and I'm hoping one of you more experienced people might point me in the right direction.

Thanks in advance!

Bulltart