damp:
slightly wet, often in an unpleasant way:

moist:
slightly wet, especially in a way that is pleasant or suitable

The same soil would be moist and damp at the same time: moist for planting seeds, and damp for sitting on.

This is the Word Choice note given by Longman Dictionary:

WORD CHOICE:

damp, moist, humid

Use damp especially to say that something is slightly wet in an unpleasant way:
• The room was cold and damp.

Use moist to say that something is slightly wet in a pleasant way or in the way it should be:
• She took a mouthful of the delicious moist cake.
• rich, moist soil

Use humid to talk about the weather or the air when it is slightly wet and makes you feel uncomfortable:
• the hot humid atmosphere of a greenhouse

damp:
slightly wet, often in an unpleasant way:

moist:
slightly wet, especially in a way that is pleasant or suitable

The same soil would be moist and damp at the same time: moist for planting seeds, and damp for sitting on.

This is the Word Choice note given by Longman Dictionary:

WORD CHOICE:

damp, moist, humid

Use damp especially to say that something is slightly wet in an unpleasant way:
• The room was cold and damp.

Use moist to say that something is slightly wet in a pleasant way or in the way it should be:
• She took a mouthful of the delicious moist cake.
• rich, moist soil

Use humid to talk about the weather or the air when it is slightly wet and makes you feel uncomfortable:
• the hot humid atmosphere of a greenhouse

Source: Longman Dictionary

damp:
slightly wet, often in an unpleasant way:

moist:
slightly wet, especially in a way that is pleasant or suitable

The same soil would be moist and damp at the same time: moist for planting seeds, and damp for sitting on.

damp:
slightly wet, often in an unpleasant way:

moist:
slightly wet, especially in a way that is pleasant or suitable

The same soil would be moist and damp at the same time: moist for planting seeds, and damp for sitting on.

This is the Word Choice note given by Longman Dictionary:

WORD CHOICE:

damp, moist, humid

Use damp especially to say that something is slightly wet in an unpleasant way:
• The room was cold and damp.

Use moist to say that something is slightly wet in a pleasant way or in the way it should be:
• She took a mouthful of the delicious moist cake.
• rich, moist soil

Use humid to talk about the weather or the air when it is slightly wet and makes you feel uncomfortable:
• the hot humid atmosphere of a greenhouse