MSB rules - what is it for?

Hi

Im not living in UK and Im a bit confused about MSB and what it is for.

I understand that there is FSA reporting and IFRS reporting so why there is the need to introduce the MSB ?

Can you tell me how it works in practice ? A comapny prepares the accounts under IFRS as it is a required standrad, does it need to prepare different reports for FSA and MSB ? What for ?

My feeling is that in the study materials there is a lot said what is the difference between MSB and FSA but it is not clear explained why it is required to do IFRS, MSB and FSA?

I lack also the comparison between FSA balance sheet and MSB balance sheet in the materials to see exactly how the numbers change under those two reporting standards.

Thank you in advance for help