What are periods in a periodic table?

What is meant by period number? What does it signify?

Periodic Table: The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number, electronic configuration, and recurring chemical properties, whose structure shows a periodic trend.

Periods are the row in the periodic table where the elements are arranged.

There are 7 such periods in the periodic table.

All the elements in the period have the same number of atomic orbitals.

For example, Every element in the top row (the $1^{st}$ period) has one orbital for its electrons. All the elements in the second row (the $2^{nd}$ period) has two orbitals for their electron.