I think anarchism is more of a broad philosophy and ethics, whereas anarcho-communism is a specific tendency or tradition. But the two can often be used interchangeably.

Within Anarchism there are many sub-tendencies. Anarcho-communism, anarcho-syndicalism, platformism etc. are extremely similar. For example, many self described syndicalists say syndicalism is a methodology whereas communism is the goal. Then there are the more individualist leaning tendencies: namely individualism and mutualism, who are more open to the market form as a possible alternative to capitalism. That being said all anarchists oppose capitalism and the state.

( the so-called anarcho-capitalists are considered a heretical tendency or a branch of neo-liberalism, most anarchists are left leaning or maybe post-left, but generally oppose capitalism.)

The names can somewhat be deceptive. For example many Insurrectionary Anarchists might see the end goal as communism but they don't explicitly identify as anarcho-communist because of certain philosophical differences with the tradition following from Kropotkin, Makno etc. For example, they have more affinities with the individualist tradition.