Is this an object destructor?

I am trying to understand a C++ code. The Following is written in the *.h file

Sys(int w, int h, Eigen::Matrix3f K, bool enableSys = true);
Sys(const Sys&) = delete;
Sys& operator=(const Sys&) = delete;
~Sys();

What is the interpretation of Line 2 and Line 3?

Are those destructors?
Why are they needed?
Is this a good practice?