Something is speckled if it is covered in small marks or specks.
The eggs in the picture are speckled.
A spectrum is the range of colors of light that we can see, in order. The order of colors is seen in a rainbow.
A spectrum can also be used to describe a range of related things, such as a "spectrum of religious beliefs".
A sphere is a three dimensional shape. It is the same shape as a ball. Because it is 3 dimensional, you can make a sphere out of clay but you can't make it by cutting it out of a piece of paper. Every point on the outside of a sphere is the same distance from the centre of the sphere.
A sphere with a map of the world printed on it is sometimes called a globe. Other objects that are almost spheres, like light bulbs, are sometimes called globes too.
