Scalability is the problem bitcoin faces, on-chain and off-chain are type of bitcoin transaction while other terms you asked for description are the possible solutions to the scalability problem. For more detail information read the below links.
Read for scalability:
The bitcoin scalability problem refers to the discussion concerning the limits on the amount of transactions the bitcoin network can process. It is related to the fact that records (known as blocks) in the bitcoin blockchain are limited in size and frequency
Read for block size:
The block size is simply the maximum limit a block can be filled up with transactions. For example, the Bitcoin block size currently stands at 1 MB
Read for On-chain and off-chain transaction:
On-chain transactions reflected on the public ledger, visible to all participants on the blockchain network while Off-chain transactions, transfer agreements between two or more parties
Read for Lighting network:
The Lightning Network is a second layer off-chain solution for Bitcoin’s scaling problem. The goal is to technologically support Bitcoin mass adoption while keeping the coin useful, affordable, decentralized, and censorship-resistant. It does this by opening payment channels between 2 users/peers that (normally would) have established relationships and don’t require trust
Read to understand first and second layer protocol and how they can be used to solve the scalability problem:
Bitcoin’s first layer, or base layer, is a protocol proposed in 2008 that has reached a global state of consensus as it approaches its tenth birthday.
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