Elasticity in technology refers to the ability of a system or application to dynamically adjust its resources—such as computing power, storage, or network bandwidth—in response to varying workloads. Elastic systems ensure optimal performance and cost-efficiency by scaling resources up or down based on demand.

Key Characteristics:
1. Dynamic Scaling: Automatically allocates additional resources during peak loads and reduces them during lulls.
2. Cost Efficiency: Reduces unnecessary resource allocation, saving costs in cloud environments.
3. Performance Optimization: Maintains consistent performance by addressing resource bottlenecks in real-time.

Elasticity in Cloud Computing:
Cloud providers, like AWS, Azure, and Google Cloud, offer elastic services, enabling users to scale infrastructure seamlessly. For example:
- Auto-Scaling Groups: Automatically add or remove virtual machines based on predefined rules.
- Serverless Computing: Executes code on-demand, scaling resources to match the exact workload.

Examples:
- E-commerce: Elastic systems handle traffic spikes during sales or holiday seasons without degrading performance.
- Streaming Services: Automatically allocate bandwidth to manage fluctuating user demand.
- Data Analytics: Scale computational power to process large datasets efficiently.

Benefits:

Improved Reliability: Prevents service interruptions during unexpected surges in demand.
Resource Optimization: Eliminates over-provisioning or under-utilization of resources.
Scalability: Enables businesses to grow without significant infrastructure changes.

Elasticity is a cornerstone of modern computing, particularly in cloud-based environments, where it supports businesses in achieving agility, cost savings, and reliability.