The broad phonological characteristics of languages

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As far as Phonology is concerned, I believe the term you are looking for is 'phonotactics', which refers to the study of how the phonemes of a given language can be arranged.

For instance, the word 'strengths' /strɛŋgθs/ contains two consonant clusters, /str/ and /ŋkθs/, but they are not interchangeable (regardless of whether its meaning is affected), meaning /ŋkθsɛstr/ —or anything starting with /ŋkθs/ or ending with /str/, for that matter— is not an acceptable word.

Other constraints such as sonority scale (which types of consonant may come before/after each other) will also play a role in determining the sequence of phonemes in a cluster.