Judicial Precedent is the process whereby judges follow prievously decided cases where the facts or points of law are sufficiently similar. This is known as stare decisis - 'stand by what has been decided' this creates fairness and certainty in the law.
It is dependant on the hierarchy of the courts and the law reports.
Hierarchy of the courts
European court of justice (ECJ) - Binds all English courts on matters of European law - EUROPEAN COMMUNITIES ACT 1972. Not binding on itself.
Supreme Court (formerly House of Lords) - appellate court - binding on all courts below it. Not binding on itself since 1966 PRACTICE STATEMENT
Court of Appeal - appellate court, bound by Supreme, binding on courts below it. Binding on itself - 3 exceptions - YOUNG V BRISTOL AEROPLANE
Divisional Courts (of the High Court) - appellate courts, bound by courts above, binding on courts below, binding on itself (some exceptions)
High Court (ordinary) - bound by courts above, binding on courts below, NOT binding on itself
Crown/county/magistrates - bound by courts above, not binding on other courts - do not set precedents.
Ratio decidendi - 'the reason for deciding'. This is the part of the judgement which creates the binding precent as in DONOGHUE V STEVENSON (snail in ginger beer) which is an orginal precedent (as there is no prievous decision before it) this created the neighbour principle which created a legal duty to 'take care not to harm your neighbour'.
Obiter dicta - 'other things said' the judge suggests hypothetical situtaton and the outcomes had they have happened, HILL V BAXTER - (swarm of bees) if attacked by a swarm of bees while driving the driver would not be at fault…