1, with different usage:

In addition, the whole phrase is equivalent to a preposition, followed by a noun or gerund as the object of to.

The other is an adverbial in a sentence, usually separated by commas.

2. Different meanings

In addition, it means not only "except" but also "other".

Except that it means "except ...".

Examples of related usage:

You need money and time. Besides, you need diligence.

You need money and time. Besides, you need to work hard.

Besides giving me some advice, he gave me some money.

He not only gave me some advice, but also gave me some money.