Immediate write off of all or part of the cost of certain qualifying property, up to a limit, by deducting it in the year you place the property in service can be an option as a 179 deduction. You can elect the section 179 deduction instead of recovering the cost by taking depreciation deductions throughout the years.
In short, qualifying property has to meet certain eligibility requirements, and it has to be acquired for business use. Property you acquire only for the production of income, such as investment property, rental property, and property that produces royalties, does not qualify.
Please note that dollar limitations may apply to the entity and individual owners separately. In other words, for example, dollar limitation is fine at partnership lever, but then disallowed to be carried forward at the individual level. Also, the deduction limits apply to an S corporation and to each shareholder. The S corporation allocates its deduction to the shareholders who then take their section 179 deduction subject to the limits.