I think that a child feels loved when their parents show interest in their lives. Giving them everything they need for success in the lives as they grow. Boundaries, rules, limits, attention, praise, outings, cuddles, and ofcoarse telling them that they are loved.
If you have healthy relationships with the people in your life, then you teach your child about healthy relationships too.
Everything that you postively teach your child helps them to feel that they are loved, because you show that you only want the best for them.