Double and triple bonds in covalent compounds signify stronger interactions and a reduced number of lone pairs of electrons.

In covalent bonding, atoms share electrons to achieve a stable electron configuration. The nature of the bond formed depends on the number of electrons shared between the atoms. Specifically, when two atoms share one pair of electrons, they form a single bond. Conversely, when they share four or six electrons, they establish double or triple bonds, respectively.

The significance of double and triple bonds in covalent structures can be understood through several key points:

1. Bond Strength: Double and triple bonds are stronger than single bonds. A double bond involves the sharing of two pairs of electrons, while a triple bond involves the sharing of three pairs. This increased sharing leads to a greater electrostatic attraction between the atoms, resulting in stronger bonds. Consequently, double and triple bonds are also shorter than single bonds.

2. Molecular Shape: The presence of double or triple bonds can influence the geometry of the molecule. In molecules composed solely of single bonds, the atoms typically adopt a tetrahedral arrangement. However, the existence of double or triple bonds alters this configuration due to a decrease in the number of lone pairs of electrons. For example, carbon dioxide ($\text{CO}_2$) has a linear geometry because of the double bonds formed between the carbon and oxygen atoms.

3. Reactivity: Molecules containing double or triple bonds often exhibit higher reactivity compared to those with only single bonds. This increased reactivity arises because the electrons in multiple bonds are more accessible and can be more readily donated to other atoms or molecules. For instance, alkenes (hydrocarbons with one or more double bonds) are generally more reactive than alkanes (hydrocarbons with only single bonds).

In conclusion, double and triple bonds in covalent compounds are crucial as they indicate enhanced bond strength, influence molecular shape, and affect reactivity. A comprehensive understanding of these bonds is essential for predicting the properties and behavior of covalent substances.