Speech-Language Pathology is a field of expertise practiced by a clinician known as a speech-language pathologist (SLP), also sometimes referred to as a speech and language therapist or a speech therapist. SLP is considered a "related health profession" along with audiology, optometry, occupational therapy, clinical psychology, physical therapy, and others. The field of SLP is distinguished from other "related health professions" SLPs are legally permitted to conclude to certain disorders which fall within their scope of practice. SLPs specialize in the evaluation, diagnosis, and treatment of communication disorders (speech disorders and language disorders), cognitive-communication disorders, voice disorders, and swallowing disorders. SLPs also play an important role in the diagnosis and treatment of autism spectrum disorder (often in a team with pediatricians and psychologists).
A common misconception is that speech-language pathology is restricted to adjusting a speaker's speech sound articulation to meet the expected normal pronunciation, such as helping English speaking individuals enunciate the traditionally difficult "r". SLPs can also often help people who stutter to speak more fluently. Articulation and fluency are only two facets of the work of an SLP, however. In fact, speech-language pathology is concerned with a broad scope of speech, language, swallowing, and voice issues involved in communication, some of which include:

Word-finding and other semantic issues, either as a result of a specific language impairment (SLI) such as a language delay or as a secondary characteristic of a more general issue such as dementia.
Social communication difficulties involving how people communicate or interact with others (pragmatics).
Structural language impairments, including difficulties creating sentences that are grammatical (syntax) and modifying word meaning (morphology).
Literacy impairments (reading and writing) related to the letter-to-sound relationship (phonics), the word-to-meaning relationship (semantics), and understanding the ideas presented in a text (reading comprehension).
Voice difficulties, such as a raspy voice, a voice that is too soft, or other voice difficulties that negatively impact a person's social or professional performance.
Cognitive impairments (e.g., attention, memory, executive function) to the extent that they interfere with communication.The components of speech production include:

phonation (producing sound)
resonance
fluency
Intonation
Pitch variance;
Voice (including aeromechanical components of respiration)The components of language include:

Phonology (manipulating sound according to the rules of a language);
Morphology (understanding components of words and how they can modify meaning);
Syntax (constructing sentences according to the grammatical rules of a target language);
Semantics (interpreting signs or symbols of communication such as words or signs to construct meaning);
Pragmatics (social aspects of communication).Primary pediatric speech and language disorders include: receptive and expressive language disorders, speech sound disorders, childhood apraxia of speech (CAS), stuttering, and language-based learning disabilities. Speech pathologist not only work with adolescents with speech and language impediments, but also those that are elderly.Swallowing disorders include difficulties in any system of the swallowing process (i.e. oral, pharyngeal, esophageal), as well as functional dysphagia and feeding disorders. Swallowing disorders can occur at any age and can stem from multiple causes.