What is Slot (Cardano)?

In the Cardano blockchain, a slot is the shortest time period (1 second). Each slot has a slot leader, who has the option of creating a single block for that slot. Though he can also choose not to create it. There are two outcomes if the slot leader doesn’t establish a block: 

• The slot remains empty because no one creates blocks in it.
• The next slot leader will be selected from a different staking pool (this wouldn’t be the case otherwise).

The Proof-of-Stake (PoS) protocol of Cardano is based on a system of slots and epochs. Each epoch is made of slots that last 1 second. An epoch of Cardano typically has 432,000 slots which are equal to 5 days. 

Though in the Byron era there were 21,600 slots in each epoch and one slot leader per slot. The Byron era was the beginning of Cardano which is now replaced by Shelley's mainnet. The Shelley era has 20 times the number of slots in every epoch in comparison to the Byron era. However, in the Shelley era, only one out of five slots have a leader.

Since there is no certainty that all slots will be filled with blocks, empty slots might appear. Empty slots can occur if no delegate wins the leadership for that slot and fails to construct a block within a certain time period. In addition, empty slots can appear as a result of network delay or the fact that network participants fail to notice winning blocks in a timely manner.

In the Ouroboros Praos algorithm (which builds on prior protocols by the IOHK team) each block is generated by a slot leader, who chooses a time slot in a random manner to produce a block. No two leaders can be active at the same time, and all blocks are built independently because of that.

What Is Cardano?

Cardano is a blockchain platform featuring the ADA governance token as its native token. Charles Hoskinson, a co-founder of Ethereum, left the company in 2014 and founded Cardano. The developers of Cardano intended to establish a scalable and secure cryptocurrency with real-world applications.

The usage of a unique layer architecture (Control Layer and Computation Layer) is a major innovation of Cardano. The Control Layer is similar to other blockchains in that it stores all of the data concerning transfers and account balances. The Computation Layer, on the other hand, operates smart contracts, as well as handles financial computations for loans and insurance policies, and so on.

Cardano's developers have great aspirations for the future. They want to make ADA a payment method that is accepted worldwide, and they're working with companies all across the world to achieve this goal. In addition, they intend to launch sidechains, which are independent blockchains that can interact with the main chain while being faster and more adaptable.