Schengen C visa - multiple entry

[VeenV]

Hi,

I am from India. I was supposed to go to Germany for business purpose, but unfortunately I could not take up the travel.
I had processed a Schengen C visa which is valid from 13 march 2011 to 30 march 2011 with duration of stay 18 days.
But it is of type multiple entry, which perplexes me. Does this multiple entry indicate re-entry within a span of these 18 days ?
I had read in some forums that Schengen C visa is valid for max 90 days.

My question is when I have to go to Germany next, do I have to again go to the embassy for processing the visa ?
Please let me know.

Thanks,
Veena.

[mulderpf]

I your visa is still valid (check the dates), then you can enter again without applying for a new one. Multiple entry allows you to enter and leave as much as you want during the time your visa is valid within certain limits with regards to total days in the Schengen area. (3 months out of six I think).

[Marcus Samuel]

Multiple entry visa: Allows you to enter the state any number of times within the period for which it is valid.