What are the Limitations of Batch Apex?

Limitations of Batch Apex:
1. The start, execute, and finish methods can implement up to 100 callouts each.
2.Only one batch Apex job's start method can run at a time in an org. Batch jobs that haven’t started yet remain in the queue until they're started.
3.Up to 50 million records can be returned in the Database.QueryLocator object. If more than 50 million records are returned, the batch job is immediately terminated and marked as Failed.
4.Methods declared as future can’t be called from Batch Apex class.
5.Up to five queued or active batch jobs are allowed for Apex.