All scripts have images, ideas, and intended meanings that actors, directors and designers draw on when interpreting a script. While images, ideas, and intended meanings are often closely linked, they also have distinguishing features.
INTENDED MEANINGS
This can be both the meanings intended by the person who wrote/devised the script and the persons who will interpret the script for an audience. The intended meanings can come from, or be linked to, various aspects of a script including its themes, plot, characters, theatre style/s, ideas, images and concepts. Basically, an intended meaning is anything the playwright wanted to be understood from a reading of the script, and/or what the production team want the audience to understand when watching the performance.
The intended meanings can also come from events in the life of the playwright which the playwright brought to the writing of the script and which has a noticeable impact upon it.
For example, Arthur Miller wrote "The Crucible" to explore the fear and hysteria that pervaded American society during the McCarthy era, using the Salem Witch Trials as an allegory. The witch trials, another case of mass hysteria and fear, summed up the emotional state of the US during this period.
The extent to which those who interpret the script keep to the intentions of the playwright or choose to create new meanings is all part of the imaginative and creative process that is theatre. We may not always fully understand (or we may interpret differently) the intended meanings of a play written a long time ago or from a culture different to our own because its meanings may be highly specific to that time or culture. However, trying to understand the original intended meanings of a script is an important part of the process of interpretation.
IDEAS and THEMES
These are the big concepts that the playwright has purposefully built their play around. Every scene of a play contains particular ideas that are being explored, and many of them are linked to the overarching themes of the play. For example, the main idea in the Banquo scene in Macbeth might be that Macbeth is (literally) being haunted by his actions. This links to an overarching theme of the supernatural, or fear of the supernatural.
THEME= Big Universal Concept, Emotions, Experiences that all human beings can relate to (like, LOVE, DEATH, COURAGE)
IDEA = The specific message, moral, or opinion about the theme
(Eg: Courage: persisting in the face of defeat is a truly courageous act.
IMAGES
Within a script images signal the look of the play, its world and the characters that inhabit it. Subsequently directors, actors and designers draw on these images to enhance the intended meaning/s of the script. Images appeal to our senses and we respond accordingly. They may be literal, but more often are symbolic or metaphorical. Playwrights and directors may incorporate recurring images into their plays, and/or have images which develop and transform as the plot is played out. Other images may only appear once in the play but may have a lasting impact on the audience. An excellent example is the image of blood and what it represents throughout Macbeth.