I'm confused about where Tomcat (standalone), JDBC and Spring boot App sit and how they communicate. Where do all three sits ? Is JDBC exist as separate JRE (sits as separate app) or execute from within the app (that is sits in app) ?? or from Tomcat (sits in tomcat) Where does tomcat sits relative to JDBC?? How tomcat use JDBC to manage connection pooling ?? If i dont use JNDI datasource will tomcat connection still pooling work? Basically how do all they create pooling ? If I dont use JNDI, will I still be able to use Tomcat's built in pooling ?

How Tomcat, JDBC and Spring boot App works together?

I'm confused about where Tomcat (standalone), JDBC and Spring boot App sit and how they communicate.

Where do all three sits ?
Is JDBC exist as separate JRE (sits as separate app) or execute from within the app (that is sits in app) ?? or from Tomcat (sits in tomcat)
Where does tomcat sits relative to JDBC??
How tomcat use JDBC to manage connection pooling ??
If i dont use JNDI datasource will tomcat connection still pooling work?
Basically how do all they create pooling ?

If I dont use JNDI, will I still be able to use Tomcat's built in pooling ?