As well as is a conjunction, it means in addition to. As well as is used when you want to emphasize one thing over the other in a list of things being spoken about. For example, She is a singer as well as a dancer. Here the emphasis is more on the dancer and hence the usage of as well as.

When approaching SC texts, you will mostly have to choose between "as well as" and "and". If the sentence does not require an emphasis on a particular adjective/noun then you must choose an answer choice that has and in it. For example, She is a singer and a dancer. Here the emphasis is equal on both the nouns.