What's coretime?

Question

1. What is coretime?
2. I do know this will affect the current parachain aution/slot model. But does this conflict with the on-demand parathread, or will it replace the existing on-demand parathread model?
3. When will this be implemented in Kusama and Polkadot? (An exact timeline isn't necessary.)
4. How can we transition smoothly to coretime model from the current auction model?
5. Upon further investigation, does a parachain slot correspond to 'bulk coretime' and an on-demand parathread to 'instantaneous coretime'? If so, please disregard question 2.

I'm sure many parachain teams are wondering about these questions. However, I've found limited resources for learning about it beyond examining the code.

And if you can provide some links to the resources while answering the questions that would be better.

Thanks!

Answer 1

1: https://polkadot-fellows.github.io/RFCs/approved/0001-agile-coretime.html

2: on-demand is going to be extended in functionality by agile coretime: If you bought a core you can make it available for on-demand (in part or full) and get a share of the generated revenue. Note: on-demand is still called instantaneous in the RFC.

3: Already rolled out on Rococo (testnet), plan to go live on Kusama in Q1.

4: Specified in the RFC: If you own a lease, you will be eligible for "renewal" on coretime.

5: yes.