3. Presentation skills

Presentation content vs. presentation delivery-Content = what we say to the target audience Speech = how we say it - the delivery in front of the audience by the speaker

6 by 6 rule (six rows per a slide and six words per a row)

4. Data storage and media

Why data storage?-Programs, data and information must be stored in nonvolatile medium: Move data to other computer, Data backup.• External storage devices differ in form, material and important properties such as:Capacity,Access speed,Access mode,Costs.

Properties of external storage devices Capacity

•Capacity- amount of data the medium can hold per area of its surface

•Access speed-amount of data that can be stored or retrieved per time unit

Access mode-refers to organization of data on the medium(random or sequential)

Compare sequential vs. direct access storage devices1)Records are organized sequentially

on the media with a logical order (ID or part number)• Eg. tracks on CD or data on magnetic tape• Not direct access, previous data must be read before reach the record in given point (magnetic tapes)

• Slower recovery of records, slower access to a single record 2)• Records are not organized sequentially

• Used on magnetic and optical disks• Data are accessed by address or location on the disk (hard drive, CD, DVD)• Faster data lookup• Direct means that no other records processing is needed to retrieve one single record (compare to sequential mode)

Hard disk drives (HDDs) and their market segments-HDD consists of: data medium,magnetic head for read/write operations,engine that rotates the platter medium.M.S-desktop,enterprise,mobile,consumer electronics.

SSD-• SSD = Solid State Drive• Competitive technology to HDD• Uses integrated circuits asmemory to store data without need of electricity power• No magnetic surface, no mechanical drive to read data• No mechanical fails• Higher price per MB than HDD

RAID-• Redundant Array of Independent Disks• Used in enterprises to protect data and enhance disk drive performance• Data are stored redundantly (eg.one record stored on two disks)and synchronized – immediate and automatic data recovery if one disk fails• RAID system is a group of several hard disks

Optical discs: CD, DVD-Advantages over magnetic disks:Less costs per megabyte than magnetic disks,More data on given surface area(DVD can store more data than CD•Disadvantages:Slower retrieval of data than magnetic disks.Blue-Ray-Optical disc storage medium designed to supersede the DVD format

Flash memory-Flash memory is a memory chip that can be

rewritten and holds its content without electric power

Factors to evaluate storage media in business-• Purpose of data storage• Amount of data to be stored• Speed of data storage and retrieval• Portability of storage devices• Cost• Reliability and life expectancy

Web-based data storage (data storage in cloud) – overview, differences to local storage-• Alternative to local data storage on HDD, DVD or flash• Provided as a service on the Internet - cloud storage• File management• File share• No physical distributions on CD/DVD, USB.(Google drive,Apple i-cloud,Sky-drive,