UASF stands for User Activated Soft-Fork, which is a type of soft fork.
While a normal soft fork requires support from the majority of miners, UASF is characterized by the fact that the soft fork is conducted by obtaining support from users who actually trade the cryptocurrency.
A soft fork is one of the ways to change the “specifications of a cryptocurrency.
The cryptocurrency system uses a technology called blockchain. The number of transactions that can be written in a single block is limited, and when the block capacity is full, the data processing speed slows down and it takes time to send money.
This is called the scalability problem, and one of the solutions is a soft fork. The specifications of Bitcoin are changed to shrink the data to be written in a block, thereby eliminating the lack of space in the block.
The soft fork method called UASF was proposed in BIP 148, which stands for “Bitcoin Improvement Proposals. 148 is a proposal number, submitted by Bitcoin Core developers and others to improve the system.
The main feature of the UASF is that although it is a soft fork, it can develop similarly to a hard fork.
In a normal soft fork, the blockchains that have been strung together diverge once, but the chains that are based on the old rules and the chains that have started to emerge according to the new rules are made compatible and converge (unify).
However, a UASF may leave the chain fragmented, just like a hard fork.