Adding to Charles' answer, the advantage of saving as SPSS data file (sav format) is that you can easily convert it to Excel or CSV format that may help you in further analysis through other tools like using SEM, Excel macros like moderation and mediation and so on. SPSS data file is relatively flexible to convert for using in other programs when needed. And, always back up your data! Free cloud storage like google drive, onebox or skydrive could be some of the options.
To add on what other scholars had shared, think surveyed data can be stored in Excel format. Reason being from Excel can convert into CSV file for SEM analysis. Excel also can copy & paste into SPSS & save as SAV file for SPSS analysis. Moreover, some online survey software / website like Google Form already saved respondents' data in Excel format inclusive open ended answers to open ended questions which can be used straight away for qualitative data analysis like color coding, sorting, searching & counting etc.
Excel and SPSS or Minitab (for example) are compatible, simply using copy and paste. For 'in the field' collection of data, holding data (when for example statistical software may not be available for laptops, tablets and phones) this is useful.
Excel also has limitations in the analysis of survey data especially for multivariate analyses (although multiple Regression is easily carried out if Toolpack add-on present).
Whether data stored on computers in excel or statistical software packages there is an ethics issue especially if the survey work is being undertaken for publication or under the auspices of an institution (such as a research group, university) or for a funded project. The key issue being confidentiality of recipient data.
If the researcher has been through an ethics process there is usually a stipulation and a responsibility of that researcher to assure confidentiality and therefore all data should be stored on password protected machines/files and probably for a specified time limit.
If this is on an instutional machine, in the cloud or shared through Dropbox or GoogleDocs the basic principle of confidentiality must apply
Thanks Roberts for referring to ethics and data confidentiality issues. Whenever storage and retrieval is concerned, researchers may need to be sure that access could be limited to only authorized individual and/or institution(s). Toolpack is a good add-on, XLSTAT could be another add-on option.
Don't forget to check out the powerful "Excel-like" online program "Google Sheets"! It is an online spreadsheet program, and you can make it as powerful as Toolpack+Excel if you just add "XLMiner Analysis Toolpak" add-on to "Google Sheets". Your current Google account would handle all these without downloading any software.
However, whenever a more powerful program like SPSS is available, Excel/Google Sheet+XLMiner may not be a preferred option as an analytical program.
Survey data may be better store as a text file. Where the responses make up the individual columns. In this form the file can be called on any software: Excel, SPSS Python and etc survey
Survey data may be better store as a text file. Where the responses make up the individual columns. In this form the file can be called on any software: Excel, SPSS Python and etc survey