A species having carbon with sextet of electrons and can act as...

A carbocation is a molecule in which a carbon atom has a positive charge and three bonds. We can say that, basically, they are carbon cations. Formerly, it was known as carbonium ion. Carbocation today is defined as any even-electron cation that possesses a significant positive charge on the carbon atom.

The carbon cations are very reactive and unstable due to an incomplete octet. In simple words, carbocations do not have eight electrons; therefore, they do not satisfy the octet rule.

In carbocation, the hybridisation of carbon will be ${sp}^{2}$ and its shape is trigonal planar. There is also a vacant $p -$ orbital which indicates its electron-deficient nature. The carbon has $6$ electrons in its valence shell. Due to this, it is an electron-deficient species, also known as an electrophile.

Six electron species