When we harvest something, we pick it from the ground or pluck it from a tree. This could be fruits, vegetables or flowers. When we "harvest now, decrypt later", we are talking about collecting information (like passwords) from a computer or a website and keeping it safe. We collect this information now, but we can't read or use it just yet because it's locked or encrypted.
It's like picking an apple from a tree and putting it in a basket. The apple is safe in the basket, but you can't eat it just yet because it still has the skin and core on it. Similarly, the passwords we collect are kept safe, but we can't use them just yet because they are encrypted.
We have to decrypt the information first to be able to use it, just like we have to remove the skin and core from the apple before we can eat it. Decryption is the process of converting the encrypted information into readable text or data. It's like cutting into the apple to make it into small pieces that we can chew and swallow.
So, "harvest now, decrypt later" means we collect the information (like passwords) first and store it safely, then we work on decrypting it to make it usable later on.