I am new to aws and I trying to understand what reserved instances are. I am searching for available p2.xlarge reserved instances and this is the screenshot of available options for 1 year

Option1) It says that the upfront price is $5022.00 and Effective rate is $0.573. Does that mean I get 5022.00/0.573 = 8764 hours ? and after finishing 8764 hours will it be on-demand pricing ?

Option2) It says that upfront price is $2562.00.Does it mean I get 2562.00/0.584 = 4386 hours ? What is the difference between effective rate and Hourly rate

Option3) It says that I don't have to pay any upfront price but the effective rate is $0.684.Does it mean I will get charged with $0.684 for every hour I use for the next 1 year ? , How is this different from on-demand instance ?

What options do you recommend If I need like 1000-1500 hours of p2.xlarge instance for the next 1 year?

Thanks in advance