RE: It's been a long time I was active here.😁 So what happened? A lot guys. So many ...

To avoid filling the chain with low quality content, each transaction depletes one's resource credits (RCs).
They're based on your SP and refill over time, just like your voting power.
As we speak, your RC bar is around 80%, meaning you could upvote 100+ times or comment 36 times, before having to slow down and let it recharge.
http://steemd.com/@modernpastor

I could double that by delegating you 100SP, which would give you more voting weight and RCs.
The new update will mean I could delegate either voting power or RCs (or both).
So applications like Splinterlands (steemmonsters) need a lot of RCs to expand their playerbase (each battle is a couple of transactions).
RC delegation pools mean I could delegate my spare RCs to them while keeping all of my voting power.