Difference in interest payable u/s 234a & 234b

Intt u/s 234A is for non-filing of return/delayed filing of return i.e after due date, calculated @ 1% per annum,

Intt u/s 234B is for failure to pay advance tax or payment of advance tax below 90% of assessed liability, calculated @ 1% per annum

The former for Return filing, the latter for advance tax.

1.234A - Interest for  Late filing of ITR.

2.234B- Interest for Failure to pay Advance Tax or 90% of assessed tax in advance (If assessed Tax more than Rs.10,000)