sql server replication: My understanding about the snapshot is,
1.Snapshot is like a starting point
2.It creates a schema and data files (most of the time)
3.It needs to be re-executed by the end of publication retention period

I have the following clarification,
I have,
Pubsliher SQL2K5
Subscribers anonymous + sql server CE
I understand snapshot is created for every subscriber while synchronizing

In the above scenario how does a re-execution of snapshot affect the
subscriber?

I'm a little confused by your post - are you saying that a new snapshot was
required when initializing, or was this your assumption and you created one.
Really, for anonymous subscribers the snapshot should stay around until the
transaction retention period is reached and can be used for new subscribers
during that period. Anonymous subscribers has been changed in SQL 2005 so
this might be a little different now - I'll check BOL for more details and
post back tomorrow. Anyway - to answer your question, the new snapshot won't
affect existing subscribers - ie this is unrelated to reinitialization and
expiration.
Paul Ibison

Thanks Paul!

One more small question. What is the need for executing the snapshot agent

The transactions will be retained in the distribution database until the
transaction retention period is reached. This means that if the snapshot is
older than that, it won't get used and you'll need a more recent one....
Cheers,
Paul Ibison SQL Server MVP, www.replicationanswers.com