Too intense a light or moving a plant from heavy shade to intense light can cause sun scalding. This is indicated by good sized bleached looking spots that turn black, crispy, and dry, looking charred. If the leaves become dark emerald green, move the plant to more light. This coloration shows that the plant wants more light to grow well. The plant will live indefinitely under lower than desirable light conditions, but it generally won't bloom.
Most orchids are epiphytic.
They grow ON trees or other plants, and they get moisture from the air. Nutrients are obtained from rain carrying decaying matter over the roots. Orchids plants must be watered somewhat differently from most plants. The size of the pot. The material the plant is potted in.