Elasticity in cloud computing allows systems to scale resources up or down automatically, according to demand. This gives the advantage of handling peak loads without provisioning for the maximum load all the time, hence avoiding outages during high traffic and saving costs during low traffic periods. High availability ensures system operation continuity but does not inherently balance resource load based on traffic. Agility offers the ability to quickly adapt to changing needs, but on its own, does not solve the issue of scaling resources according to varying traffic. Improved security is crucial for protecting data and applications, but it does not address the scaling based on traffic volume.