No, a replication snapshot is totally different from a database snapshot. Basically what applying the snapshot means is that all objects which are part of your publication are (re)created in the subscriber database and when the data is bcp'd into the tables. Depending on the size of your database and the network connection between the two servers, applying the snapshot can take some time. Until the snapshot is applied you can not change the data on the subscriber. Once the process is finished it should work, though if you're using transactional replication it's usually not a good idea to make changes on the subscriber.
Hope this helps
[font="Verdana"]Markus Bohse[/font]