To cast a spell, you must be able to speak (if the spell has a verbal component), gesture (if it has a somatic component), and manipulate the material components or focus (if any).
Holy Symbol, Silver or Wooden: A holy symbol focuses positive energy. A cleric or paladin uses it as the focus for his spells and as a tool for turning undead. Each religion has its own holy symbol.
Spell Component Pouch: A spellcaster with a spell component pouch is assumed to have all the material components and focuses needed for spellcasting, except for those components that have a specific cost, divine focuses, and focuses that wouldn’t fit in a pouch.
Divine Focus (DF): A divine focus component is an item of spiritual significance. The divine focus for a cleric or a paladin is a holy symbol appropriate to the character’s faith.
If the Components line includes F/DF or M/DF, the arcane version of the spell has a focus component or a material component (the abbreviation before the slash) and the divine version has a divine focus component (the abbreviation after the slash).
To cast a spell with a somatic (S) component, you must gesture freely with at least one hand. You can’t cast a spell of this type while bound, grappling, or with both your hands full or occupied.
To cast a spell with a material (M), focus (F), or divine focus (DF) component, you have to have the proper materials, as described by the spell. Unless these materials are elaborate preparing these materials is a free action. For material components and focuses whose costs are not listed, you can assume that you have them if you have your spell component pouch.