What is electron configuration?

Hint: The electron configuration of any element describes how the electrons will be distributed in its atomic orbitals. the configuration follows the standard notation while distributing the electrons in a proper sequence.

Complete answer:
Let us understand the basics of electron configuration;
Electron configuration is in short, the summary of electrons around the nucleus. The electrons are filled up into the sequential orbitals in a dignified sequence. The order of electrons which are placed in those shells depends on the order of energy they carry. This is known as Aufbau’s principle; as stated below,

This is the sequence in which the electrons are being filled in the shells around the nucleus. For example;
$_{11}Na=1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{1}}$
Sometimes, the condensed notation is used instead of standard notation i.e. $_{10}Ne=\left[ He \right]2{{s}^{2}}2{{p}^{6}}$ .
The above-described configuration denotes the energy level, type of shell/orbital along with number of electrons as-

The electron configuration is used to determine the valency of an element, interpret atomic spectra and predict the properties of similar types of elements.

Note:
Do note that there are exceptions to the electron configuration discussed above. The two main exceptions are shown by chromium and copper. In these cases, completely or half-filled subshells are more stable than that of partially filled d-orbital. So, an electron is excited from 4s subshell towards a 3d orbital.