Babu, In general Informatica Hotfix is like enhanced sub version of Informatica software and where as EBF (Emergency Bug Fix) is a packaged software to resolve server/ client-side components.
Refer the hotfix release notes and EBF package notes for details
in simple words:
An EBF (Emergency Bug Fix) is developed for resolving a customer(s) specfic issue and should only be applied after it was suggested by Informatica GCS only as an EBF can have conflicts with already applied EBFs.
A Hotfix is an collection of several EBFs and Bugfixes. If you apply an Hotfix it will resolve many issues with a single installation. An Hotfix is going through Q&A certification and Informatica recommends to apply Hotfixes.
You can find more information about EBFs and Hotfixes in below mentioned guide:
Hope that helps