a) Converge sequence will have a limitation on the magnitude of its term, but diverge sequence has not limitation.

For example,  magnitude of time of a toy car’s motion on rough road likes a converge sequence, it will get a certain magnitude. Magnitude of time of this car’s motion on frictionless road without obstacle likes a diverge sequence, it will get infinite.

b)Converge series will have a limitation on the magnitude of its terms’ sum, but diverge series has not limitation.

For example, if an immortal apple tree have 5 apples in a infinite space at first and it will generate an apple everyday. And the apples will get off from the tree and never decay.  The number of apples likes a converge series if there is always an animal eating an apple. The number of apples likes a diverge series if there is nothing interfering fruiting.