This is a large and complex topic. Assuming you are a new student to phonetics/phonology, a skeleton view will give you an orientation. "Distinctive features" is a technical term meaning analysis of phonological characteristics that underlie phonetic elements of a given language. Phonemics are the sound pairings that create languages. For example, Xhosa has different phonemic parings e.g., /xh/) than English does. In Xhosa, lip pops, tongue clicks, and glottal clicks all comprise phonemes that have understood meaning, while in English, these clicks and pops are merely noises. The phonological features of articulation (i.e., realization of sounds) underlie the function of producing meaning in phonemic pairings.
Discussion of distinctive features of phonology directs attention to a specific analysis of the potential "matrix of features" of phonemes originally proposed by Jakobson, then furthered by Chomsky and Halle and others. Jakobson's distinctive features describes phonemes in terms of acoustic features (Robert Mannell, Ph.D., Macquarie University). This analysis has as its foundation the concepts of (1) opposition and the (2) definitive qualities of phonemes as they relate to meaning in language and the (3) defining acoustic descriptions.
(1) Opposition: Jakobson's distinctive features comprise binary opposition, also called privative opposition: a phoneme has or has not a certain feature, e.g., a phoneme is or is not nasal; is or is not voiced; etc. This binary, privative opposition is shown with + and - symbols: [+nasal] [-nasal] [+voiced] [-voiced], etc.
(2) Definitive Sets of Features: In any language, it is a small set of features that determine variation between phonemes (units of meaning); in other words, phonological features that underlie phonemic pairings are an identifiable set and not an exhaustive set.
(3) Distinctive Features are Acoustic Features: Simply put, Jakobson's insights were/are applied to acoustic rather than articulatory descriptions. For example, articulatory description may consider idiosyncratic realizations, such as whether or not you add a /p/ articulation in realizing "Chomsky" to articulate it "Chom/p/sky." It might be said that acoustic description of distinctive features considers what it is rather than what you make it.
The major classes of distinctive features are these binary (privative) oppositions: syllabic (syllable nucleus), consonantal (obstruction,e.g., +/-glottalization), sonorant (periodic energy, e.g., +/-low frequency), continuant (air flow, e.g., +/-sibilance), and delayed release (aspiration phase, e.g., +/-stops); analytic charts present these classes in this order. These are abbreviated as syll cons son cont and delrel. Other distinctive features describe the source of vibrational quality of airstream and present the opposition of (1) voiced or glottal and the opposition of (2) continuant or sibilant. Distinctive features of vowels consider the binaries of height (high/low e.g., /eh/ /oh/), backness (back/front e.g., /o/ /a/), roundedness (round/not round e.g., /w/ /k/), and tensity (tense/lax, e.g., /ah/ /ee/). There are a number of other distinctive features that Jakobson identified, two of which are anterior/posterior and labial/non-labial.