The difference between maintenance and alimony matters because Indian judgments and petitions usually say maintenance, while search engines and clients say alimony.
Maintenance
Maintenance is support so a dependant spouse or child can meet reasonable needs. It can be claimed in several statutes, including CrPC/BNSS-linked maintenance, personal law, and protection from domestic violence proceedings. It may be interim or final, monthly or in a lump sum.
Alimony
Alimony is the popular label for post-divorce spousal support. A divorce alimony calculator is still estimating maintenance-style figures, not a guaranteed decree.
Use the alimony calculator and the maintenance calculator as planning tools, then take the printout to counsel.