List using curly brackets (braces) in formula to create a list

Hi,
I've been experimenting with using curly brackets (after watching tutorial, excelcampus) to create return multiple columns in
an index function.
Look up area B4:G13
INDEX(B4:G13,SEQUENCE(ROWS(B4:G13)),{4,3,1})

to return column 4 then 3 then 1.
I've also looked at the match function to return multiple results;

MATCH(M2:O2,B4:G4)

My question is ; can someone explain or tell me where I can find information on how these work for example 'index({1,3,4},2,3,5}) returns R1C2,R3C3,R4C5.

I've attached the file I've been messing with 'sheet 2 ' better. I know it's a bit vague but in help gratefully recieved.

Not sure what this formula is meant to be index({1,3,4},2,3,5}) but even if it's meant to be index({1,3,4},{2,3,5}) then it cannot return R1C2,R3C3,R4C5. For the simple reason there is only one row & 3 columns, so it would return 3,4,#REF!