What is the difference between Egld and Elrond?

Could you please elaborate on the key differences between Egld and Elrond? I'm particularly interested in understanding their functionalities, use cases, and any distinctive features that set them apart from each other in the cryptocurrency sphere. Additionally, how do they compare in terms of scalability, transaction speed, and cost-effectiveness? It would be helpful if you could provide a concise yet comprehensive comparison between these two cryptocurrencies.