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An “entity” of a database model is a logical construct. A “table” of a database is a physical construct. Both are expressions of the same concept. For example the table “person” represents what we would logically think of as a “person”.To put a finer point on it, the attributes of the logical “person” construct map closely to the columns of the physical construct so that each tuple in the entity - row in the table - models a person for the needs of the business.Note the lack of quotes on person there. That is because in the last usage the word person is about the concept as you think about it in your head when you hear the word rather than the limitation we would impose upon it in a model.A bit about logical v. physical modelsA logical database model is concerned with the business rules, reference data, primary and alternate keys. In the purest of sense, this model would have no concern for the database engine (Oracle, MySQL, etc) it will be implemented upon.A physical database model is the implementation of the logical model with changes made for the reality of the underlying database engine. Once the logical model is ready to be implemented physically:entities become tables (your specific example)primary keys become the primary key constraintalternate (or natural) keys become unique indexesAn example of this translation might look like this:I am handed a logical model in its most pure form. I am told to implement it on MySQL using InnoDB. The logical model does not use surrogate (logical term) or physical (physical term) keys. These are the commonly found auto incrementing, sequenced integers used as a primary key.Because, as a physical DBA, I know that InnoDB writes data to disk as leaf nodes of the primary key constraint, I know that I will get much faster look ups if surrogate keys are used. I work with the logical modeler (or take on the task myself) to implement them so the engine will perform for business needs (as well as the model itself).Other general examples:Take keys from the logical model and implement them differently in the physical model based on the way query optimizers work.Denormalize a entity relationships for performance.Create a unique column in a reference table to ensure that the application code does not use surrogate keys directly. (improved app code maintainability)

Simple. Learn the "LOGICAL MODEL " and learn start up you will gain a vast experience in management. The world has a ton of resource which you dont need to dive deep for. If you're not sure what logical model means, MIT has an good example that I used for my project management world. Since then, I've customized to my own level and upgraded their design to my work style. Good luck. mit project logic model

Mathematics studies numbers, geometry, and form. Those require definitions and axioms to characterize the subjects of study. Logic is used to prove properties based on those definitions and axioms.Logic can also be used in ordinary discourse of nonmathematical topics.Typically, the logic needed for mathematical investigations is great while that for nonmathematical investigations is small.On the other hand, mathematics is used to study logic. Models for logic are mathematical entities.