what is symbolic link in solr. Is there any concept exist in solr related to schema..? Is it related creation of class object specified in schema.xml.. ?
Symbolic link is a concept in computing not in Solr.
In computing, a symbolic link (also symlink or soft link) is a special type of file that contains a reference to another file or directory in the form of an absolute or relative path and that affects pathname resolution.
One of the exaple when you need symbolic link is, if you install solr using package manager then it installs default configuration files (schema.xml , solrconfig.xml). So, you need to replace this default configurations with yours by creating a symbolic link.
Check this post, it could give you an idea.