class of trees or graphs

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Here we can see how to generate all the trees of order $n$ and is not upto isomorphism. But I dont want all trees of order $n$.

I want to know is there class of graphs which are particular typres of trees, like class of paths.

In general where I can find how to define class of complete graph, cycles, . . .

Kindly share the link for the documentation.

Thank you.