An issue of a periodical is one book that contains a collection of essays. The issue numbers typically start at "1" at the beginning of each year. Inside the issue, you will find the article you are citing. The volume of a periodical is the entire set of issues published in a single year. You can locate a particular article by knowing the year of publication, which would tell you in which volume the article appeared, and then by knowing the issue number, which would tell you the printed book it is in.
Volume is also a measure of space. If you want to know the amount of space that matter takes up, you will need to calculate the volume of an object. For example, if you want to find the volume of a cube, you will need to multiply the height, length and width together. The volume, or available space, of an object is important to know while cooking, moving and packing, taking medicine and more.
Volume can also describe how loud you perceive a sound to be. Volume is not a precise measurement of sound, such as the decibel or the intensity of a sound. Volume is a perceived, psychological measurement of loudness. For example, although reverberation or resonance does not affect the intensity of a sound, every element affects the volume of a sound. A sound with the same number of decibels will appear louder if there is more reverberation than if there is no reverberation, and so you would consider the volume higher.
You can also consider an issue to be synonymous with a question or dispute. When participating in a debate, for example, you receive an issue, or dispute, to discuss. After reading about and studying the issue, you would need to take a side and argue for it. The beginning of a research paper often identifies an issue. For example, many research papers briefly explain a topic issue, which is in question, along with a narrowed thesis statement in the first paragraph.
Issue is also a verb that can mean "to send." The military uses this term frequently. For example, the military often "issues" uniforms to enlisted members. However, the term also appears in casual political language. An example of this is in emergencies, when aid agencies issue blankets and food, or send them out to hurricane or flood victims.