Hard Zoning vs Soft Zoning!

Dear All,

Please let me know the function and difference between soft/hard zoning. Suppose if the hba of the server or the sfp on the switch is faulty then what is the impact on both the zones and how we will be able to correct them.

For Example:

In hard zone: If switch sfp is faulty then after changing the sfp, we have to create zone again or what we have to do?? and also same in the soft zoning case.

In hard zone: if the server hba is faulty then after changing the card, we have to create the zone again or what we have to do?? and also same in the soft zoning case.