What is ELK Stack ?

ELK Stack is designed for users to gather data from any source and search,analyze and visualize them in real time .The word ELK stands for,

E - Elasticsearch 

L - Logstash

K - Kibana

 This technology helps user by providing centralized logging that can be beneficial for the users when trying to analyze the problems within server or applications. User can search every single log within one place and it will help the user to find bugs in multiple servers by connecting to all the logs. 

At the process of ELk these steps will  have to occur in order to make a successful outcome.

1. Logs : Server logs needed to be analyzed and identified .
2. Logstash : Gather logs and event data.(Might even parse & transform data)
3. Elasticsearch : The transformed data of Logstash store,search and indexed .
4. Kibana : Kibana uses Elasticsearch DB to Explore, Visualize, and Share.

Advantages

• Offers a host of language clients which includes  Python. PHP, Perl, .NET, Java,Ruby and JavaScript, and more.
• Easy Deployment.(horizontally & vertically)
• Ability to provide various libraries for different programming languages and scripting languages. 
• Many logs can be searched in one place.

Disadvantages

• Trail & error.
• Can be difficult to handle when moving on to a complex setup.

refference https://www.elastic.co/what-is/elk-stack