Queueable apex is an asynchronous apex method. It’s similar to the @future method. By using this queueable interface, we can process an Apex that runs for a long time (such as web service call outs and extensive database operations). The job isadded to Apex job queue. System. en-queue Job method returns the job id; so, we can easily monitor its progress, either through the Salesforce training UI in the Apex Jobs page, or by querying the record using AsyncApexJob object. Benefits of Queueable Apex: 1. Queueable apex supports the Non-primitive type member variables, such as SObject or custom apex types. 2. Systematization method returns the AsyncApexJob record id. Use this id to find your job and Monitor its progress. 3. You can chain one job with another job. Limitations : 1. Count against shared asynchronous method call limit. 2. Can add only up to 50 jobs with in single transaction. 3. Only one job does the call out in chaining. Syntax : 1.Implement Queueable Interface Publ