This is the first event in multi part series which will cover payment channels & the Lightning Network. This event will focus on the scaling challenges Bitcoin is faced with & some of the early attempts to address them. We will first cover "Nakamoto high-frequency transactions," Spillman-style payment channel & CLTV-style payment channels. We will discuss their constructions, shortcomings & examine example transactions.

Once complete, we will examine (at a high level) Decker-Wattenhofer duplex payment channels & Poon-Dryja payment channels. Lastly we will discuss Hash Time-Locked Contracts & the function they serve in the Lightning network. At future events we will take a closer look at some of the BOLTS in the Lightning-RFC & have workshops where attendees can spin up an lnd node & connect channels to one another.

You can read through this wiki (and do your own further research) to come prepared:
https://en.bitcoin.it/wiki/Payment_channels