The cell model defines how each cell in Nervos acts and interacts with each other, and the process must be followed for updating the data contained within the cells. People familiar with Bitcoin’s UTXO model may notice the similarities, because the cell model was inspired by it.
Cells are immutable. This means no changes can be made once cells have been added to the blockchain. For any data update, the containing cell must undergo a process called consumption. When a Cell is consumed, data gets extracted and the cell gets destroyed. The data can be updated as needed while being extracted. A new cell with updated data will then be created and added to the blockchain.
Each Cell can be consumed only once. A non-consumed cell is known as a live cell. A consumed cell is known as a dead cell. Once dead, the cell can no longer be used.
Transactions serve to explain the changes in cell data. The transaction specifies a group of live cells to consume and a group of new cells to create by using the updated data. The network validates the transaction by executing all lock scripts and type scripts of each cell contained in the transaction. This ensures that all rules defined by the developers are being followed without any fraud.