I would like to know if Synaptic package manager can install an application from a .tar.gz file downloaded from a different source than is in the repositories in /etc/apt/sources.list.
I mean those files need to run ./configure , make, sudo make install to install. Does Synaptic perform these operations?
Those file where we need to run ./configure , make, sudo make install are archives with source code of the application in it.
Synaptic is a graphical management software for installing debian packages with all it's dependencies. Those debian packages are precomplied and to put it simply they are just archives containing the binaries and configuration files.
Most modern Linux distributions have a similar systems because compiling every single program by yourself can be partly very painful.
To answer your question: No there is no option to give Synaptic a source package to install it from source, you have to do this by hand.
But, in most cases you will find an other repository or a PPA or even a .deb package for this piece of software.
