Answer may be:

Suppose you are new in business and just launched your application with a single server. After some time your business started growing exponentially which brings more traffic to your website but as you had a single server, and traffic on the website exceeded the capabilities of the server, customers are facing low latency issues. To overcome the problem you need to distribute the traffic across the servers. Now in traditional cases, customers will report low latency then you will check for the problem and get servers installed by spending huge capital. This will be time-consuming, hectic, and dissatisfactory.  Instead of this wouldn’t it be better if there is some service that can automatically do it for you? Introducing Amazon Elastic Load Balancer or ELB

Types of AWS Load Balancing techniques:

AWS offers three types of Elastic Load Balancer

• Application Load Balancer.
• Network Load Balancer.
• Classic Load Balancer.

For more details, read the full blog:

What is AWS Elastic Load Balancing (ELB)?