Data Separation
SegWit introduces an additional structure, often referred to as the “extended block,” allocated specifically for witness data.
Streamlined Blocks
This restructuring means more transactions can be squeezed into the standard 1 MB block size.
Immutable Transaction IDs
By relocating witness data outside of the transaction’s main body, SegWit ensures the transaction ID (or txid) remains unaffected by alterations to this data, cementing its immutability.
Foundation for innovation
Thanks to the removal of malleability concerns, advancements like the Lightning Network have a reliable groundwork to build upon.