I am slowly coming to the end of watching "Toaru Majutsu no Index" anime. There are few anime series related to that world:

Toaru Majutsu no Index

Toaru Majutsu no Index II

Toaru Kagaku no Railgun

Toaru Kagaku no Railgun S

and some movies. But I am not sure in what order I should watch them. Someone told me that "Railgun" came after "Majutsu no Index" - should I watch "Railgun" first then, or the second season of "Index"? Are there some things that I can miss if I watch them in the wrong order, like not knowing characters that were already introduced?

And if it is Railgun I should watch second, should I watch "Toaru Majutsu no Index II" afterwards, or "Toaru Kagaku no Railgun S"? Or it really doesn't matter and I can watch both "Toaru Majutsu no Index" series before "Toaru Kagaku no Railgun" series?

I am slowly coming to the end of watching "Toaru Majutsu no Index" anime. There are a few anime series related to that world:

• Toaru Majutsu no Index
• Toaru Majutsu no Index II
• Toaru Kagaku no Railgun
• Toaru Kagaku no Railgun S

and some movies. But I am not sure in what order I should watch them. Someone told me that "Railgun" came after "Majutsu no Index" - should I watch "Railgun" first then, or the second season of "Index"? Are there some things that I can miss if I watch them in the wrong order, like not knowing characters that were already introduced?

And if it is Railgun I should watch second, should I watch "Toaru Majutsu no Index II" afterwards, or "Toaru Kagaku no Railgun S"? Or is it that it really doesn't matter and I can watch both of the "Toaru Majutsu no Index" series before the two "Toaru Kagaku no Railgun" series?