The general anatomy of a syllable, using an English word as an example:
The basic division is that between an onset, consisting of consonants or semivowels, and a rime, consisting of a vocoid and possible further elements. This structure is seen in almost all natlangs (the infamous counterexample is Arrernte).
In English, onglides usually belong in the onset (strives rhymes with chives), but in other languages, this is not necessarily the case.
The vocoid is the sonority peak of a syllable. It is usually a vowel, but it can be a consonant as well. Such a consonant is almost always a sonorant, and will be call'd a syllabic consonant. It is not uncommon for there to exist tighter rules for the structure of syllables with a consonantal vocoid, typically limiting the possible on- and offglides. In a sense, a syllabic consonant may itself occupy the glide slot, with the main vowel slot empty (see eg. Mandarin).
The most common example of an extrametrical consonant, seen in our example as well, is the Indo-European s-mobile. Extrametrical consonants can be identified by their phonotactical properties: English syllables can feature an extrametrical /s/ (or /ʃ/) only before /m n p t k/, and these are also the only cases where another consonant can occur before these (it is debatable if /s/ in /sw, sl/ and /ʃ/ in /ʃr/ are extrametrical).
It is possible for extrametrical coda consonants, such as the English plural/possessiv //z//, to not contribute to syllable weight.