Every Indian print shop offers roughly four bindings, they are rarely explained, and the decision is usually made at the counter at ten at night. Here is what actually separates them.
Spiral binding
A plastic or metal coil through punched holes. It is the cheapest, the fastest, and the only one that lets a document lie completely flat or fold back on itself — which matters if anyone has to write while reading it.
Best for: college projects, lab records, drafts, anything under about 200 pages. The default for a reason.
Against it: pages can tear out of the coil with heavy handling, and it looks informal.
Comb binding
A plastic comb with teeth through rectangular holes. Similar cost to spiral, and its one real advantage is that it can be opened and re-closed, so pages can be added later.
Best for: documents that will be updated. Manuals, reports in progress.
Against it: does not lie as flat as spiral, and the comb spine cracks if the document is thick.
Soft binding, also called perfect binding
Pages glued into a card cover with a flat printed spine, like a paperback. Noticeably smarter than spiral for a similar order of cost.
Best for: a thesis or dissertation submission where the department has not demanded hard binding, and anything that will sit on a shelf and needs a readable spine.
Against it: does not lie flat, and the glue can fail if the document is very thin or very thick.
Hard binding
A stiff board cover, usually with the title stamped in gold or silver. The most expensive and the slowest — often a day or two, because it is generally sent out to a specialist.
Best for: a final thesis, when the university specifies it. Many do, in writing.
Against it: cost, time, and the fact that it cannot be corrected. A typo found after hard binding means paying for the whole thing again.
The two things to check before you decide
First, the department's rules. Universities that require hard binding say so in the submission guidelines, and a spiral-bound thesis handed in against those rules is refused at the desk. Read the guidelines, not the advice of the person ahead of you in the queue.
Second, proofread before you bind. Binding is the last step and the only irreversible one — every binding above costs more to redo than the printing did.