What is the network difficulty in aeternity?

Could you please explain in layman's terms what the network difficulty in aeternity refers to? Is it a metric that measures the complexity of transactions on the blockchain? How does it impact the overall performance and security of the aeternity network? Are there any factors that can affect the network difficulty, and if so, how do they influence it? Additionally, how does the network difficulty in aeternity compare to other blockchain networks? Thank you for your insights.