Lightning Network
Lightning Network allows users to transfer BTC to each other at no charge using their digital wallets. A second layer is added to the Bitcoin network to allow transactions between some points on the chain, called off-chain transactions.
Lightning Network creates payment channels between two users in a distributed database so they can transact with each other without other users receiving their information. It was designed to speed up transaction processing and reduce associated costs on the Bitcoin blockchain. It was invented in 2015, is being developed and used to this day.
However, researchers have warned that as the Lightning Network grows, so do the chances of it becoming a target. According to experts from the Hebrew University of Jerusalem the Bitcoin locked in the payment channel of the Lightning Network, which today is about $ 9 million in Bitcoin, can be stolen. While the price tag is serious researchers believe it can be fixed in the long run.
Segwit
Segregated Witness, or SegWit, refers to a process change in how Bitcoin holds transaction data on the blockchain. This allows the network to hold more transactions in a single block. SegWit came into active on Bitcoin in August 2017.
SegWit increases the block size limit of a blockchain by removing signature data from Bitcoin transactions. Not only did it improve the processing speed of transactions but it also solved a weakness in the protocol that allowed nodes to create problems by violating the transaction flaw (TXID) on the network.
On the Bitcoin network, the SegWit update was introduced as a soft fork in August 2017. The soft fork includes a new rule that does not conflict with the existing ones.