Electric field intensity is a vector quantity. This means that it has both magnitude and direction. The magnitude of the electric field intensity is a measure of how strong the electric field is at a given point. The direction of the electric field intensity is the direction in which a positive charge would be pushed if placed at that point.
A scalar quantity is a quantity that has only magnitude. For example, temperature is a scalar quantity. The temperature of a room is a number that tells you how hot or cold the room is. It does not tell you in which direction the heat is flowing.
A vector quantity is a quantity that has both magnitude and direction. For example, velocity is a vector quantity. The velocity of a car is a number that tells you how fast the car is going. It also tells you in which direction the car is moving.
Electric field intensity is a vector quantity because it has both magnitude and direction. The magnitude of the electric field intensity is a measure of how strong the electric field is at a given point. The direction of the electric field intensity is the direction in which a positive charge would be pushed if placed at that point.